Memoirs MCZ 2603

Umoirs of

ilje

Museum

of

Comnaratibe Zoology

AT HARVARD COLLEGE.
Vol.

XXVI.

No.

3.

REPORTS ON THE SCIENTIFIC RESULTS OF THE EXPEDITION TO THE
TROPICAL PACIFIC, IN CHARGE OF ALEXANDER AGASSIZ, BY THE
U. S. FISH COMMISSION STEAMER " ALBATROSS," FROM AUGUST,
1899, TO MARCH, 1900, COMMANDER JEFFERSON F. MOSER, U. S. N.,
COMMANDING.
III.

MEDUSA
BY

ALEXANDER AGASSIZ

and

ALFRED GOLDSBOROUGH MAYER.

WITH THIRTEEN PLATES, AND A CHART OF THE ROUTE.

[Published by permission of

Gbouge M. Bowbhs,

U. S. Commissioner of Fish aud Fisheries.]

CAMBRIDGE,
$rintcb for

tfje

U.

S.

A.

:

IHusntm.

January, 1902.

Reports on the Scientific Results of the Expedition to the Tropical
Pacific in charge of Alexander Agassiz by the U. S. Fish Commission
Steamer "Albatross," from August, 1899, to March, 1900, Commander
Jefferson F. Moser, U. S. N., commanding.
III.

MEDUSA.
By

ALEXANDER AGASSIZ AND ALFRED GOLDSBOROUGH MAYER.

(Published by permission of Geo. M. Bowers, U. S. Commissioner o£ fish and Fisheries.)

INTRODUCTION.
The medusae

described in the following paper were obtained in thirty-

four surface hauls, and in one bottom trawl

made

at

830 fathoms

in

the

In addition to these there were thirteen intermediate hauls with

Marquesas.

an open net, one at 100 fathoms, five at 150 fathoms, and seven between

250-350 fathoms and the

The hauls

in

surface.

which medusae were captured were distributed

Between San Francisco, Cal., and the Marquesas
Among the Marquesas, Paumotus, and Society Islands
.

Total

.

as follows:

—

EXPEDITION OF THE "ALBATROSS,"

140

1899-1900.

region of the Japan current north of the Ladrones the water teemed with
life,

and the display

fact

it is

phosphorescence at night was truly remarkable.

of

In

evident that pelagic animals are not abundant in regions far from

large land masses or where there are no well defined oceanic currents or

As soon

counter currents.

as one approaches the region of great currents

or counter currents, or the coasts of continents and larger islands, the

number

of animals increases with remarkable suddenness.

was very noticeable that during the daylight hours our surface tows

It

were generally deficient

in

animal

while those

life,

made

at the

same time

with an open net at depths varying between 300 fathoms and the surface

were remarkably rich

obtained.

It

both in

evident that in the regions

is

unknown depth during

animals sink to an

noted that these same animals
surface hauls

made

cessful than those

Among

number and

at night

made

the

we examined

the daytime.

rise to the surface

is

in the

free expanse of ocean

same

It should also

during the night, for our

The

relatively great

In

continents.

number of the

the

open

sea,

however, they
in

the

Rhopolonema, Aglaura, and Liriope,

There were, however, two

young

of

between California and the Marquesas were wonder-

Leptolina forms were captured near some coast or

A

suc-

number

Our hauls

pelagic types.

while yEgina and Solinaris were met with occasionally.

:

be

locality during the day.

fully rich in such Trachylina forms as

rule

pelagic

the

quite striking, for these medusae are rare in waters

coasts of

constituted the greater

archipelago.

specimens

were almost without exception much more

Trachylina and thirteen Leptolina forms.

adjacent to

the

Hydromedusas obtained by the " Albatross," seven are

the twenty

the Trachylina forms

of

variety

Sarsia

where the nearest land

was obtained
(the

in

among

remarkable

N. Lat.

Almost

9° 45',

all

of the

the islands of an

exceptions to this

W. Long.

137° 47',

Marquesas) was more than 1000 miles away

;

In general, how-

and a Tiara was found 600 miles north of the Marquesas.

1
ever, the results support the conclusions of Maas, in the case of the Plankton

Expedition, that Leptolina forms are creatures of the shallower waters near
coasts, while the

1

Trachjdina are animals of the open ocean.

Maas, O., 1893; Craspedoten Medusen der Plankton-Expedition. Also
Marine Animals, Natural Science, London, Vol. II., p. 02—99.

Distribution of

On some Problems

of the


;

.

MEDUSAE.

The following

table will serve to

141

show the extent of our captures:

Number

of Species
obtained.

Hydroinedusse

Number
new

8

4

Siphonophorae

10

4

4

2

42

21

The following forms
Atlantic

by

are represented

of Species
already known.

11

Scyphomeduste
Ctenopborae

Number

of Species

to Science.

20

.

—

21

both the Tropical Pacific and

in

identical or very closely allied

species

:

Aglaura prismatica,

Liriope hyalina, Nausithoe punctata var. pacifica, Abyla quincunx, Necto-

physa Wyvillei

?

DESCRIPTION OF THE SPECIES.

HYDROMEDDS^l.
Sarsia

A

single specimen of a

young

sp.

damaged condition was

Sarsia in a greatly

found on the surface when the nearest land (the Marquesas Islands) was

remarkable that

over 1000 miles away.

It

have been taken so

out upon the open ocean.

S-';

«

far

Station 13

;

is

September

5,.

1899

;

N. Lat. 9°

Tiara oceanica,
Plate

The

bell is

and there

medium

is

size,

acorn-shaped and 5

1

Long. 137°

47'.

1, fig. 1.

mm.

in height.

and sixteen short tentacles.

The

walls are very thin,

There are eight long, eight

The long ones

The medium
;

f

W.

are about as great

tentacles are about one-third as

—

S)
S d indicates a surface tow made in the daytime S" a surface tow made at niirht (150 f
made with an open net dragged between 150 fathoms and the surface during the day
S)" indicates the same made at night.

indicates a haul

(150

57',

form should

sp. nov.

a small, solid, apical projection.

in extent as the bell height.

this Leptolina

—

;

rf


EXPEDITION OF THE "ALBATROSS,"

142

and the small ones are mere rudiments.

long,

The

from the hell-margin.

1899-1900.

All of the tentacles arise

and intermediate ones

basal bulbs of the long

are conical, and each one bears a single ocellus upon

The velum

base.

is

by means

aboral side near the

There are four narrow radial tubes,

well developed.

the mid-regions of which display jagged edges.
the radial canals

its

The

proboscis

is

The

proboscis

is

of four mesenteries.

bound

to

short and

extends only about one-half of the distance from the inner apex to the

The gonads occupy

velum.

four radially

The

surfaces of which are complexly folded.

much

The

folded.

and the

the

four lips are large and are

proboscis and tentacle bulbs are of a delicate purple-pink

A

dark red.

ocelli are

situated linear swellings,

was found about 600 miles

single specimen

north of the Marquesas.
(250

f

—

Station 1G; September

S)'';

9,

1809; N. Lat. 2°

Turris pelagica,
Plate

The

bell

is

mm.

16

wider at the middle than

The

projection.

bell walls are

about thirty short tentacles,
arise

are

no

The velum

ocelli.
flat

any other

is

There

end.

is

very thin and quite

being of the same

size.

a small, solid, apical
flexible.

There are

These tentacles

all

There

conical.

and quite broad, being narrower near the circular canal than
Their outer edges are jagged, excepting in the narrow

place.

part of the bell-cavity.
four mesenteries.

The

It

is

developed, complexly crenulated
light port-wine color,

numerous

lips.

The

and the gonads and

single specimen of this
Station

1

;

by means of

from the inner apex

of the

surfaces of the gonads are
papilla?.

lips

There are four well

and tentacle bulbs are of a

radial canals are of a

medusa was found

August 26; N. Lat. 31°

the greater

radially situated double rows

The outer

transversely folded and give rise to

fills

to the four radial canals

of the distance

opening.

large and

is

The gonads occupy four

bell-cavity to the velar

S'';

proboscis

bound

which extend about two-thirds

A

being

There are four radial tubes

well developed.

parts near the circular canal.

shade.

22'.

sides are barrel-shaped,

from the bell-margin, and their bases are large and

which are
at

all

Long. 137°

1, fig. 2.

either

at

W.

sp. nov.

and the

in height,

38',

10',

W.

still

lighter

in a surface haul.

Long. 125°.


MEDUSAE.

PSYTHIA,

143

gen. nov.

Williadae with four simple unbranched radial canals.

In

all

known genera

previously

The general form,

are branched.

of the family Williadae the radial canals
color,

budding of the present medusa, however,
the Williadae.

may

It

atavistic sport

medusa-buds before attaining

its

Plate

its

may

flatter

give rise

much

shrivelled b}' con-

ascertained.

It

radially situated tentacles, each of

one-half as long as the bell-height.

composed of chordate

cells,

The entoderm of

and a very

fine

throughout the length of each tentacle.
radial canals

;

appeared,

than a hemisphere, and 4 nun. in diameter.

The gelatinous substance was of uniform and only moderate
stiff,

to

1, fig. 3.

exact shape could not be

however, to be slightly

There were four

among

sp. nov.

In the single specimen obtained, the bell was
so that

it

complete development.

Psythia prolifera,

traction,

to place

from some of the more

an immature individual which

or

Williadae,

one

incline

all

be a primitive, or ancestral, form in which the canals

have remained simple, or possibly an

complex

shape of proboscis, and method of

thickness.

which was about

these tentacles

axial canal appeared to

There were four

and a simple, slender, circular canal.

was

extend

straight, simple,

The

proboscis was

cruciform in cross-section, and about three-quarters as long as the height
of the bell-cavity.

The four

lips

were small and slightly recurved.

Four

medusa-bearing stolons arose from the four radial corners of the stomach

very near the points of entrance of the four radial canals.
stolons gave rise to from

When

opment.

tentacles and

about

two

to

to six

radial canals, as in

sprinkled over with nematocyst

stolons

is

ochre-yellow,

of these

in various stages of devel-

be set free the young medusa possesses four simple

trace of the proliferating stolons.
is

medusa-buds

Each

all

the adult

;

but

The ex-umbrella
cells.

its

proboscis shows no

of the

The entoderm

other parts being colorless.

young medusa

of the proboscis

A

and

single specimen


EXPEDITION OF THE "ALBATROSS,"

144

1899-1900.

of this medusa was obtained, in an open net towed between 300 fathoms

and the surface,

i—S) J

(300

off
;

Marokau

Island,

Station 136; October 28, 1899; S. Lat. 18° 08', VV. Long. 141° 49'.

Lymnorea
Plate

The top

as

about

The

broad.

is

it

of the bell

short

fifty

a

The

and the sides

mm.

sp. nov.

9-12.

2, figs.

about 4

is

flare

outward

in diameter,

bell-walls are thin,

and quite

and

in a bell-shaped
is

about as high

flexible.

There are

tentacles which are each about one-half the length of

stiff

entodermal cores are

cells.

ocellata,

These tentacles are usually carried curled upward, and

the bell-height.
their

flat

is

The animal

manner.

Paumotus Group.

and composed of vacuolated chordate

solid

basal bulbs of the tentacles are large, and each one

mass of red pigment.

In addition to this there

is

a prominent ectoder-

mal ocellus upon the ventral (lower) side of each
distance centrifugally from the basal
are four straight, narrow radial

peduncle of the proboscis

is

bulb.

contains

tentacle

The velum

is

at

short

a

There

small.

The

canals and a slender circular tube.

wide and quadratic

cross-section,

in

and

its

lower portion, near the gastric region, consists of highly vacuolated ento-

dermal

cells.

mouth

is

The

gastric part of

a simple round opening.

the proboscis

The

entire

is

pear-shaped, and the

proboscis extends

about

one-half the distance from the inner apex of the bell-cavity to the level
of the velar opening.

one of which

is

There are four well developed

oral tentacles, each

about half as long as the height of the proboscis.

Each

oral

tentacle branches dendritically four times, thus giving rise to sixteen distal

knobs.

Each knob

thickly covered with a bristling cluster of fusiform

cells.

In addition to these there are several patches of nema-

bristles

upon the sides of the main trunk of each oral tentacle.

nematocyst
tocystic

is

The gonads

are developed

of the proboscis.

in four radial

The entoderm

of the tentacle bulbs

The ectodermal

part of

the proboscis

number

of these medusas were obtained

Makemo

Island,

is

regions within the gastric part

brick-red.

and of the gastric

ocelli

are black.

A

on the surface in the lagoon of

Paumotus, on October 23, 1899.


MEDUSAE.

145

Bougainvillia fulva Agassiz and Mayer.

p. 162, PI. 2,

Agassiz and Mater, 1899

fulva

Bougainvillia

Mus. Comp. Zool., Vol. XXXII.,

Bull.

;

Fig. 6.

Plate

2, fig. 8.

individual of this species was found

An immature

by us among the

Fiji

Islands in 1898, and a mature specimen was obtained off Funafuti Atoll,
Ellice Islands, on

The
cal.

bell

is

December

about 6

22, 1899.

mm.

in

The gelatinous substance

height and the sides are straight and vertiis

There

of uniform thickness everywhere.

are four bunches, each containing seven tentacles, which arise from the bases
of the four radial canals.

chordate.

cells are

A

These tentacles are

solid

single dark-colored ocellus

is

and their entodermal

upon the under

situated

The velum

or centripetal side of each tentacle near the basal bulb.

There are four

narrow.

The proboscis

vessel.

is

straight, narrow, radial canals

quadratic, and

its

base

is

is

and a slender circular

wide.

It

extends about

one-third of the distance from the inner apex of the bell-cavity to the velar

Four

opening.

oral tentacles, each of

which branches dichotomously four

times, arise from the four radial corners of the proboscis near the mouth.

The mouth

The entoderm of

proboscis.

The

A

The gonads are

a simple round opening.

is

the proboscis and tentacle bulbs

tentacles are of a translucent milky color, and the bell

single

fathoms

specimen was obtained

in

is

rosin-yellow.

transparent.

an open net towed from a depth

f

—

S)''; Station

195; December

1899; S Lat. 10°

22,

Epenthesis rangiroae,
Plate 1,

The

is

of

150

to the surface.

(150

The

situated in the

bell

bell-walls are thin

and

W.

Long. 179°

is

7

30'.

sp. nov.

Jig. 4-

slightly flatter than a hemisphere,

is

47',

and

mm.

in diameter.

There are sixteen well developed

flexible.

tentacles with large conical basal bulbs.

Sixteen otocysts, each containing

a single spherical otolith, alternate in position with the sixteen tentacles.

The velum

is

broad.

narrow circular

vessel.

There are four

The proboscis
10

straight, slender, radial canals,
is

very short and quadratic

and a

in cross-


EXPEDITION OF THE "ALBATROSS,"

146

and there are four slightly recurved

section,

1899-1900.

The four gonads are

lips.

found upon the four radial canals very near to the circular
single specimen obtained, each

The medusa

eggs.

gonad contained from

six to eight

prominent

transparent with the exception of the proboscis gonads

is

and tentacle bulbs, which are translucent and milky in

was found

In the

vessel.

This form

color.

lagoon of Rangiroa Island, Paumotus, on September 23,

in the

1899.
(150

f— S) d

;

Station 195;

December

22,

1899

;

S. Lat. 10° 47',

Phortis elliceana,
Plate

The

much

bell is

flatter

2, figs.

is

5-7.

the bases of the four radial canals.

mm.

about 16

is

in

There are about

sharp-edged.

is

Four of these are

hollow tentacle bulbs.

30'.

thick at the aboral pole, but becomes

thinner towards the bell-margin, which
fifty-six

Long. 179°

sp. nov.

than a hemisphere, and

The gelatinous substance

diameter.

W.

Twelve others are

three of these are found in each quadrant.

and are situated at

large,

medium

of

size,

and

In addition to these there are

about forty very small rudimentary tentacle bulbs upon the bell-margin.

There are no

marginal

lateral or

which alternate

in

cirri.

There are about

position with the tentacle bulbs.

two or three spherical

The velum

otoliths.

is

fifty-six otocysts

Each otocyst contains

four simple, narrow, radial canals, and a slender circular vessel.
cle is

There are

well developed.

The pedun-

about as long as the bell-diameter, and projects a considerable distance

The

beyond the bell-opening.

basal part of the peduncle has the shape of a

four-sided truncated pyramid, while the distal portion

gradually toward the gastric part of the proboscis.

extend down the angles of the

The

proboscis.

latter

recurved, crenulated

is

proboscis

is

is

The

long, and tapers

four radial canals

peduncle to the gastric portion of the

short and flaring, and there are four well developed,

The gonads

lips.

are linear, and are developed

the sub-umbrella regions of the radial canals.
bulbs and gonads

is

The entoderm of

the tentacle

pink in color, while that of the gastric portion of the

A

rosin-yellow.

single specimen of this

medusa was found

an open net which was towed from a depth of 150 fathoms

to the

f

— Sy

;

Station 195

;

December

22, 1899; S. Lat. 10° 47',

W. Long.

179°

in

surface,

off Funafuti Atoll in the Ellice Islands.
(150

upon

30'.


MEDUSAE.

Rhegmatodes
Plate o,

The

bell

is

sp. nov.

lacteus,

fiys. 15, 16.

than a hemisphere, and

flatter

gelatinous substance

147

about one-tenth as long as the bell-diameter.

tentacles,

These ten-

In addition to these

tacles are provided with large hollow, bulbular bases.

large tentacles there are about 250 very small rudimentary

There

ones.

are about 500 otocysts, each containing two small spherical otoliths.

velum

delicate

is

There are 105

and narrow.

upon the middle and lower regions
stomach

proboscis

mm.

25

is

in diameter,

and the canals

and there are 105 simple

short,

is

arise

5,

1899:

Mesonema macrodactylum Brandt,
Tom. IV.,

p.

A

single specimen

S. Lat.

17°

W.

27',

J. F., 1838;

Long. 149°

32'.

Brandt.

Mem. Acad. Imp.

Petersbourg, Sci. Nat.

St.

359, Taf. IV.

Large numbers of

this

medusa were found swimming

at the surface in

the lagoon of Likieb Atoll, Marshall Islands, on January 20-21, 1900.
tentacles are not quite so long as in Brandt's figures.
canals, tentacle bulbs,

medusa being

the

Pacific,
it

The

tentacles, proboscis,

color.

Mesonema macrodactylum
G,

The

lips.

periphery.

its

The

haul a few miles north of Tahiti.

in a surface

Station 73; October

Ser.

from

The

radial canals,

gonads are developed.

and genital organs are of a translucent milky

was found

narrow

straight,

of which the

A

extends downward

bell,

There are ten well developed

almost to the level of the stomach.
is

The

in diameter.

thick at the apex, but thin at the bell-margin.

is

long funnel-shaped depression, at the apex of the

each of which

mm.

50

is

and

lips is slightly

colorless.

and Chun (1896

;

milky

Brandt describes

Mitt. Nat. Mus.

The

The entoderm of the

in color

;

all

other parts of

this species

from the tropical

Hamburg, Jahrg.

13, p. 7) records

from the coast of Zanzibar.

Polycanna purpurostoma

Agassiz and Mayer.

Polycanna purpurostoma Agassiz and Mayer, 1899
p. 1G9, PI. 8, Figs.

A

single specimen of this medusa, 50

a surface tow

We

found

it

;

Bull.

Mus. Comp.

Zobl., Vol.

XXXII.,

26-28.

made

among

off

Tahaa

mm.

in

diameter, was obtained in

Island, Society Islands, on

the Fiji Islands in December, 1897.

November

16, 1899.


;

EXPEDITION OF THE "ALBATROSS,"

148

1899-1900.

Liriope hyalina Agassiz and Mater.
Liriope hyalina Agassiz and

Mayer, 1899;

Mus. Comp.

Bull.

XXXII.,

Zobl., Vol.

166,

p.

PI. 9, Fig. 32.

Specimens of

this

medusa were found by the " Albatross

quesas, Paumotus, Society, Ellice,
especially

common

We

(300

f— S)",

rf
;

Station 13

"

rf

f

— S)

d
;

September

—

S)'';

1899

7,

"

;

"

137°

«

2° 38',

"

137°

16

9,

"

"

25

"

14,

"

S"

"

31

"

19; S. Lat. 12° 20',

October 22

November

Station 173;

"

W. Long.
Lagoon of Makemo Island,
S. Lat. 18° 55', W. Long.

;

4

;

17; off

December 22;

Station 195;

"

;

January

Bora Bora

very

flat,

Islands, Marquesas.

15'.

Paumotus.
146° 32'.

W.

Long. 179°

30'.

;

paciflca,

3, figs. 13,

Islands.

sp. nov.

U.

being about three times as broad as

The

in diameter.

22'.

Island, Society Islands.

S. Lat. 10° 47',

Plate
bell is

144°

1897-98.

47'.

Lagoon of Funafuti, Ellice Islands.
1900; Lagoon of Likieb Island, Marshall

25
20,

57',

Between Ua Iluka and Marchand

Dipleurosoma

mm.

137°

6° 41',

"

S";

23

W. Long

"

S";

S"

The

X. Lat. 9°

S";

S";

(150f

this species in the Fiji Islands in

5,

"

14

;

S";

(100

found

and they were

;

open ocean between California

in the tropical part of the

and the Marquesas.
S
S

and Marshall Islands

" in the Mar-

surface of the ex-umbrella

it

is

high, and

by a

reticulated

is

regular system of hexagonal elevations bounded by shallow furrows.

There

are about one hundred short tentacles with narrow bulbular bases.

entodermal core of these tentacles

At

is

solid

and composed of chordate

the bases of most of the tentacles, upon the lower side, there

black ocellus.

is

otoliths.

cells.

a single

Slender club-shaped sensory bodies are scattered at frequent

and irregular intervals between the tentacles.

bodies

is

The

solid,

and very similar to that of the tentacles.

The velum

is

narrow.

from diametrically opposite

the eight canals.

The gonads

bifurcate,

There are no

In the single specimen

and thus eight canals reach the

are linear and occupy the middle region of

Their surfaces are slightly papillate, and the ova stand

out as hemispherical protuberances.
direction of the

core of these

Six radial canals arise in groups of three

sides of the stomach.

examined two of these canals
circular vessel.

The entodermal

The stomach

two opposed groups of

radial

is

canals.

elongated

in

the

The proboscis

is


149

MEDUSAE.
very

short,

bulbs, genital organs,

and proboscis are milky white,

A

medusa being transparent.
haul about

is

tentacle

other parts of the

in a surface

miles north of Tahiti.

fifty

Plate 4,
bell

all

was obtained

single specimen

Geryones mexicana,

The

The

six small, slightly crenulated lips.

and there are

fig.

broad and pear-shaped and

gelatinous substance

is

17.

mm.

about 5

is

The

in diameter.

very thick at the aboral pole, but becomes thin

There are

near the bell-margin.

nov.

sp.

six large, hollow, interradial tentacles, the

centrifugal sides of which are provided with wart-like nematocyst-bearing

There are

swellings.
arises

from the

also six slender, solid radial tentacles, each of

There

above the margin.

side of the bell at a short distance

which

are six otocysts which are situated near the bases of the six interradial tentacles.

Each otocyst contains a

developed.

There are six straight

The entoderm

observed.
tentacles

and there are

The

is

of a

delicate

proboscis

A

pink.

well

radial

is

short and

No gonads were

six slightly recurved lips.

of the proboscis,

is

which are wider near the

radial canals

proboscis than they are near the circular vessel.
lacks a peduncle,

The velum

single spherical otolith.

and interradial

canals,

medusa was

single specimen of this

obtained in a surface haul off the coast of Mexico.
S<*;

Station 3

;

August

28, 1899

;

N.

Lat. 26° 18',

Carmaris rosea,
Plate

The

bell is hemispherical,

nous substance

is

margin, which

is

W.

Long. 128°

54'.

sp. nov.

4, fig. 18.

and about 6 mm.

in diameter.

The

gelati-

thick at the aboral pole, but diminishes toward the bell-

sharp-edged.

There are twenty-four

twenty-four distinct lappets upon the bell-margin.

between each successive pair

of tentacles.

Two

incisions,

forming

lappets are situated

There are twelve

tentacles.

Six

of these, which are long, flexible, and hollow, are situated at the bases of
the six radial canals.

nematocyst

cells,

These tentacles are thickly covered with rings of

and are about as long as the bell-diameter.

The

six other


EXPEDITION OF THE "ALBATROSS,"

150

tentacles are solid, and are interradial in position.

1899-1900.

Their centrifugal sides

are studded with about six to ten wart-like, neinatocyst-bearing swellings.

These tentacles are about as long as the
stiffly

There are twelve otocysts, one

upwards.

Each otocyst
six broad,

developed.

and are carried curled

at the base of each tentacle.

There are

hollow and contains a single spherical otolith.

is

flat,

bell-radius,

upon the mid-regions of which the gonads are

radial canals,

In addition to

the

are eighteen blindly

canals there

radial

between each successive pair of radial

ending centripetal canals, three

Six of these centripetal canals are longer than the others, and

canals.

extend about half the distance from the bell-margin to the base of the
stomach.

The

The

proboscis

circular canal

The velum

flat.

is

well developed.

long and pyriform, and the mouth projects beyond the level

is

The mouth

of the velar opening.

narrow neck, and there are
of the medusa

wide and

is

situated at the extremity of a long

is

of a delicate rosy-pink,

is

and

A

other parts are colorless.

all

was found in a surface haul made south

single specimen

The entoderm

six short, slightly recurved lips.

Marquesas

of the

Islands.
S'';

Station 31

;

September

19,

1899

S. Lat. 12° 20',

;

W. Long.

144°

15'.

Aglaura prismatica Maas.
Aglaura prismatica Maas, 1897; Mem. Mus. Comp.

XXTIL, No.

Zool., Vol.

1,

p.

24, PI.

III., Figs. 4, 5.

We

thereafter

it

became one

it

to be

commonest

of the

among

bers were obtained

we found

c

obtained this medusa in N. Lat. 12

first

7',

W. Long.

137° 18'

objects in the tow.

;

and

Large num-

the Marquesas and Society Islands, and in 1897

abundant among the

Fiji Islands.

1

It

was discovered

in

considerable numbers by the "Albatross" off the west coast of Mexico and

Central America in 1891, and

it

seems

safe

to

conclude that

it

is

distributed over the tropical regions of the Pacific.
SJ

(300

f

September

4,

1899

S'';

"

13;

"

5,

"

S";

"

15;

"

8;

— S)";

"

25;

"

73

S"

S"
1

;

Station 12

;

;

Bull.

;

;

"

October 5

November

14

;

N. Lat. 12°

1

7

;

off

18'.

137°

47'.

"

4° 35',

"

136°

54'.

Islands.

W.

Bora Bora

Mus. Comp. Zool., Vol. XXXII.,

Long. 137°
"

Marquesas

;

W.

9° 57',

S. Lat. 17° 27',

;

07',

"

Long. 149°

32'.

Island, 'Society Islands.

p. 1G5, PI. 4,

Fig

13.

widely


MEDUSA.
Mgina,

Two

151

sp.

specimens of iEgina were obtained

dragged from 250 fathoms
diameter, and
tentacles.

One

to the surface.

f

—

S)
;

too

much damaged

Station 1G; September

9

;

Solmaris

were brought up

in

were of a milky-yellow

much damaged

N. Lat. 2°

38',

W.

Long. 137°

22'.

the other 40

mm.

in

diame-

sixteen tentacles, and the gonads

Unfortunately the margins of their

color.

bells

were

for specific identification.
1,

1899; N. Lat. 17°

Solmissus marshalli,
Plate

5,

Jiffs.

32',

W.

Long. 135°

40'.

sp. nov.

33-25.

disk consists of a thick doubly convex, central portion, and a thin

mm.

outer annulus or collar region, and

is

00

nous substance of the central region

is

very

region

in

sp.

They each had

(150 f—S)''; September

The

them was 28 mm.

an open net which had been dragged between 150

fathoms and the surface.

too

of

for description.

Two specimensof Solmaris, one 25 mm. and
ter,

an open net which was

they both possessed four slender, slightly greenish-colored

They were
(250

in

is

flexible.

Fourteen equally spaced

periphery of the central disk.
conical insertion base.

rigid,
stiff

diameter.

in

The

gelati-

while that of the collar

tentacles arise from the

Each tentacle possesses a well developed

The entodermal

cells

of the tentacles are chordate,

and are very thin and much crowded together.

A

well developed peronial thickening extends radially outward from the

base of each tentacle to the outer margin of the collar region.

Owing

to

the specimen being in a somewhat imperfect condition, only one sense organ

could be observed upon the outer edge of the collar region.

contained a single highly refractive otolith of remarkably small

velum

is

well developed, and

animal through the water.

its

This one
size.

The

powerful contractions serve to propel the

The stomach

is

wide and

flat,

and gives

rise to

fourteen radiating pockets which are situated in the radii of the tentacles.

EXPEDITION OF THE "ALBATROSS,"

152

The mouth

is

a simple round opening at the centre of the sub-umbrella.

The fourteen gonads are

situated at the centripetal edges of the fourteen

The gonads and

stomach pockets.
while

1899-1900.

tentacles are slightly milky in color,

A

other parts of the medusa are transparent.

all

obtained off Kwajalong Atoll, Marshall Islands.

single specimen was

came up

It

in

an open net

which had been towed between 150 fathoms and the surface.
(150f

— S)f

Station 220; January 1G, 1900; N. Lat. 8° 38',

;

Rhopalonema typicum
Homceonema typicum Maas,

Mem. Mus. Comp.

1897;

W.

Long. 167°

37'.

Maas.
Zobl, Vol. XXII.,

p.

22, Taf.

III.,

Figs. 1-3.

Plate 5,

Maas
with

found

describes this species from the west coast of Mexico.

on September

it

especially

common
3°

abundant about
bell

projection.

is

7,

1899, at N.

lat.

made

in surface hauls

north of the equator

at night,

We

long. 137°.

in

W.

The

largest

specimen

are very thin but are remarkably

of
stiff

20

mm.

and

is

We

also

It

was

a small solid apical

by us was about 15 mm.

The

in breadth.

rigid,

bell-walls

swimming being accom-

by means of the strokes of the powerful velum which

ingly flexible.

met

long. 137°.

obtained

Maas records one

first

and appeared to be most

broad and hemispherical, and there

in diameter, but

plished

W.

6° 41',

Marquesas and Paumotus Islands, and at Tahiti.

at the

it

The

21-22.

figs.

is

exceed-

There are eight well developed tentacle bulbs situated at
In addition to these there are about

the bases of the eight radial canals.

twenty-five or thirty smaller tentacles which are interradial in position.

seems probable that the shafts of

all

of the tentacles

were broken

the specimens found by us, leaving only the basal bulbs.

It

off in all

There are about

sixteen exceedingly small otocysts upon the bell-margin, each one of which

The velum

contains a single spherical otolith.
of

its

powerful muscles cause

it

The

proboscis

rower than the mid-region.

is

large, and the contractions

to vibrate with

well developed system of circular muscles

sub-umbrella.

is

is

found

remarkable rapidity.
in the

A

ectoderm of the

urn-shaped, the proximal part being nar-

There are four recurved

lips.

There are

gonads, one upon the middle region of each of the radial canals.

six

Young


MEDUSAE.

153

individuals are of a glassy transparency, while older ones are slightly trans-

lucent and milky in color, especially in the proboscis, gonads, and marginal
tentacles.
s*

September

7,

15;

"

8,

"

16;

"

9,

"

"

31;

"

19,

"

"

32;

"

20,

"

Station 14

s»

"

s»
s»

S"

;

1899
"

S"

"

23,

s»

"

24,

October

S"

;

41',

"

4°

35',

"

"

2° 38',

"

137°

S. Lat. 12° 20',

"

144°

15'.

"

145°

42'.

"

"

13°

37',

Long. 137°.
136° 54'.
22'.

Lagoon of Rangiroa Island, Paumotus
Avatoru pass, Rangiroa.

"

off

"

off Pt.

5,

W.

N. Lat. 6°

Islands.

Venus, Tahiti.

SCYPHOMEDUS-E.
Charybdea grandis,
Plate

The

Adult Medusa.
It
is

is

interradial,

is

of a

wing-like

mm.

A

them

into

flexible

distal

end

mm.

broad

the

sides of

which extend outward

mm.

The

pedalium.

the

long, and

its

of the

portion

surface

(Fig.

is

28).

tentacle,

flexible

part of

which

arises

and

Four sense

organs,

knob-shaped and

is

is

about

ringed and covered with transverse rows
or

rhopalia

is

(Figs.

Each sense organ

from a deep niche situated about 27 mm. above the

The sense organ

from the

the tentacle

29, 30), alternate in position with the four tentacles.

velarium.

long,

wide canal extends through the substance of each of

of nematocyst cells

arises

There are four

These pedalia are each about 40

25 mm. wide.

of

The gelatinous substance

in diameter.

remarkably tough consistency.

pedalia,

in a radial direction.

the

26-31.

high and cone-shaped, with a blunt apex.

is

230 mm. high, and 140

quite thick and

140

bell

6, figs.

sp. dov.

level of the

mounted upon

a short

stem, and contains from one to three ectodermal ocelli, and an entodermal
otolith.

In old medusae there

organ, but in a

and two small

is

usually a single, median ocellus in each sense

young specimen 30 mm.
lateral ocelli.

objects within the bell-cavity.

pended by four mesenteries, or
Twenty-four short

These

in

height there was a large median,

ocelli are all directed so as to

The velarium

is

perceive

well developed and

is

sus-

frenulae, in the regions of the sense organs.

tree-like velar canals (Figs. 26, 31)

extend centripetally


154

EXPEDITION OF THE "ALBATROSS,"

1899-1900.

The

proboscis

inwards into the substance of the velarium.

there are four slightly recurved

short,

is

and

There are four interradial crescentic

lips.

areas of numerous, short gastric cirri; the horns of each crescent pointing

outward from the stomach.

radial pouches extend

Four wide

centripetally.

These pouches are separated one from another by four interradial

partitions,

but are placed in communication one with another by means of the lateral

lumen of the

canals leading into the
leaf-like folds

The gelatinous substance of

the bell

translucent and milky white, and the gastric

is

deep

rhopalia are dull ochre in color and the ocelli are

We

of

Fakarava Island, Paumotus.

of

mature individuals
This species
(300

f

— S)

rf
;

far the largest

solid,

Eight

stiff

14,

1899;

off

Fakarava

"

15,

"

off

Anaa

quite

tentacles,

flat

and

is

17

sp.

mm.
is

Paumotus.
Paumotus Islands.

nov.

in

diameter.

interradial

short

cirri.

is

The mouth

a cruciform

slit

groups of gastric

with the

lips.

Each of

There are eight

about as long as the bell-radius.
tentacles.

is

Each sense
There are

otolith.

sixteen prominent marginal lappets which alternate in

sub-umbrella, and

swarm

33.

7, fig.

each of which

tentacles and sense organs.

a large

Atoll,

Island,

marginal sense organs alternate with the

in position

— almost

to the surface, south

organ contains a centripetal ocellus and a centrifugal

Four

of the

Charybdea known.

October

Plate
is

flexible

Island, floating very near the surface of the

Nausithoe picta,

bell

and

brown

The next day we discovered

Anaa

off

by

is

S*;

The

cirri

The

found a single specimen of this medusa in an open net

first

which had been towed from a depth of 300 fathoms

sea.

hyaline.

is

The sensory knobs

parts of the tentacles are pink or yellow-pink.

black.

consist of eight

attached to the sides of the interradial septa? and hanging free

in the radial pockets.

entoderm

The gonads

pedalia.

position

with the

situated at the centre of the

surrounded by four simple, short
cirri

lips.

are arranged so as to alternate

these groups contains about a dozen

There are eight large gonads which

In the female the ova are large and prominent.

lie in

the tentacular radii.

In the sub-umbrella there


MEDUSA.
is

155

a well developed system of circular muscles which forms a ring, the outer

circumference of which meets the bases of

edge coincides

in position

the tentacles, while the inner

with the middle points of the gonads.

In addition

to these circular muscles there are sixteen strands of radial muscles

which

extend outward on either side of the gonads to the middle of the lappets.

There are

muscle strands in the ex-umbrella which extend

also eight radial

outward toward the sense organs, and

in addition to these there are eight

well developed groups of radial muscles at the bases of the eight tentacles.

The stomach
and

wide lenticular space at the centre

consists of a

pouches extending outward

this gives rise to eight radial

Each of these pouches

the eight sense organs.

of branches into the lappets,

bell

brown

color,

bifurcates and sends a pair

The

ocelli

cirri

are dark blue.

specimens, one male and the other female, were found at night on the

15° 22',

Rangiroa Island, Paumotus, on September 24,

W.

Nausithoe punctata
XXXII., p. 170.

var. pacifica

eight

disk

is

quite

flat

tentacles which

solid

Agassiz and Mayek.

Agassiz and Mayer, 1899

var. pacifica

Plate

The

and

is

are

about 4

quite

on the sub-umbrella edge of the disk.
lappets,

two between

The eight sense organs
situated

at

the

mm.

rigid.

Eight gonads

in

Mus. Corap.

Zool., Vol.

each

There are

in diameter.

These tentacles are each

They

arise

from sockets

successive

pair

of

sense

cleft

organs.

alternate in position with the eight tentacles, and

bottom of the niches between the lappets.

ova are large and

opening

Bull.

There are sixteen sharply

sense organ contains a centrifugal otolith and
ocellus.

;

7, fig. 3<2.

about three-quarters as long as the bell-diameter.

marginal

in S. lat.

long. 147° 57'.

Nausithoe punctata

the

The

and gonads are of a rich

and the entodermal core of the gastric

surface south of

are

in the radii of

in all sixteen terminal pouches.

translucent and milky in color.

is

Two

making

of the disk,

lie

in

a

centripetal dark-brown

the eight tentacular radii.

prominent.

The mouth

Each

is

a

In the female

simple

cruciform

the centre of the sub-umbrella, the arms of the cross, passing

through two

of the tentacular diameters.

There are four groups of gastric


'

EXPEDITION OF THE "ALBATROSS,"

156

which alternate

cirri

position

in

with the

these groups contain from four to seven
is

slightly bluish or

milky

in color,

Each of

of the medusa.

lips

The gelatinous substance

cirri.

and the genital organs are dull cream or

In the majority of specimens there are no spots

slightly ochre colored.

upon the ex-umbrella, but
upon the upper surface
differ

1899-1900.

in

some there

a brownish or yellowish spot

is

This form appears to

of each of the eight lappets.

from the Atlantic-Mediterranean species only

in its duller coloration

and the frequent absence of spots upon the ex-umbrella. Compare the Figure

we

here present with the drawing of the Atlantic species given in the Bull.

Mus. Comp. Zool., Vol.

We

XXXVIL,

Plate 26, Fig. 87.

obtained this medusa in considerable numbers in Neiafu Harbor,

Vavau

Island,

among

the Fiji Islands in December, 1897.

Tonga, on December 5 and

specimen obtained near Suva,

1899, and

we

Our Figure

is

6,

also found

it

taken from a

Fiji.

Atolla Alexandri Maas.

Fig.

Atolla Alexandri Maas, 1897
2, Taf. XIV., Figs. 4, 5.

A
at

;

Mem. Mus. Comp.

single specimen, in good condition,

Zool., Vol. XXIII.,

was brought up

No.

1, p.

81, Taf.

XI,

bottom trawl

in a

830 fathoms between Ua Huka and Marchand Islands, Marquesas, on

September

14, 1899.

was 24 mm.

It

diameter, and there were forty-

in

A

eight marginal lappets and twenty-four tentacles.
of this deep-sea form

made

off

number

were obtained by the "Albatross"

in

of specimens

1891

in trawls

the Pacific coasts of Mexico and Central America.

Linerges aquila Haeckel.
Linerges aquila Haeckel,

An immense swarm
diameter, were

found

October 27, 1899.

with

in

of
in

ephyra)

the

Syst. der

E., 1880;

of this

lagoon of

Medusen,

p. 496.

species, all

Ilikueru

about 3

Island,

mm.

in

Paumotus, on

Another swarm of somewhat older medusa? was met

the lagoon of Funafuti, Ellice Islands, on

December 24-25; and

a single mature individual was captured in the lagoon of Rongelab Atoll,

Marshall Islands, on January 17, 1900.

We

ephyra) and mature medusae of this species
1

found large numbers of both

among

Agassiz and Mayer, 1839; Bull. Mus. Comp. Zool., Vol.

the Fiji Islands in 1897.

XXXII.,

p. 170, PI. 10, Figs. 33, 34.


MEDTJS.E.

Zonephyra corona,
Plate

The

bell

a

is

becomes

but

umbrella
short

near

thinner

hollow

nov.

more than a hemisphere and

little

the

and

tentacles

is

quite

thick

nematocyst

eight

marginal

in

aboral pole,

the

surface

of

the

ex-

There are eight

cells.

Each sense

organs.

sense

mm.

about 15

is

at

The

bell-margin.

with

thickly sprinkled

is

sp.

4, figs. 19, 20.

The gelatinous substance

diameter.

157

organ contains an entodermal mass of red-colored granules.

There are

thirty-two broad lappets, two between each successive tentacle and sense

The sub-umbrella

organ.

provided with a well developed set of circular

In addition to these there are sixteen spear-head-shaped radial

muscles.

muscle

is

strands

strands are

in

sub-umbrella

the

;

the

ends

broad

of

these

muscle

These strands extend to the notches between

centripetal.

each successive tentacle and sense organ.

Sixteen narrow radial muscle

strands are also found in the ex-umbrella, and they alternate in position

The

with the strands of the sub-umbrella.
shaped, and

there

are four

proboscis

recurved, crenulated

is

broad and

The

lips.

flask-

four gonads

are interradial in position and are horseshoe shaped, the concavity being
directed outward.

Each gonad

is

thrown into complex corrugations, and

in

the female the eggs are easily seen on account of their deep purple color.

Each gonad

provided with from eight to ten gastric

is

cirri.

The

gastro-

vascular cavity extends outwards in thirty-two pockets, one in each lappet.

The

gelatinous substance of the bell

is

of a greenish-amber tinge.

The

entoderm of the tentacles and the sensory entoderm of the marginal sense
organs

is

of a claret color, as are also the eggs.

gastro-vascular cavity

is

The

of a delicate claret color,

entire entoderm of the

and the radial muscle

strands of the sub-umbrella are of a glistening white.
of this

medusa was found.

It differs

A

single specimen

from the two species described by

Haeckel, 1880, in that there are thirty-two lappets instead of sixteen as in
Haeckel's forms.
Sd

;

Station 14

;

September

7,

1899; N. Lat. 6°

41',

W.

Long. 137°.


EXPEDITION OF THE "ALBATROSS,"

158

Pelagia tahitiana,
Plate

Immature
about 16

The

individual.

mm.

sp. nov.

8, Jigs. 34, 35.

disk

twice as broad as

is

The ex-umbrella

in diameter.

1899-1900.

is

it

high, and

is

is

quite regularly sprinkled

over with large wart-like papillae which bear nettling

cells.

The

papillae

near the aboral apex of the disk are larger than the others, those near
the bell-margin being very
distal

three-quarters of

There are eight hollow

small.

tentacles, the

which are covered profusely with nettling

cells.

These tentacles are each about three-quarters as long as the bell-diameter.
Eight marginal

sense organs

organ contains a mass of dark-red

There are sixteen

partially

four well developed

long as the

of

which

is

Each

(centripetally).

entodermal

The mouth

There are four

shaped,

gonad

of

is

palps which are about

crenulated

horseshoe

pigment

cleft lappets.

bell-diameter.

Each sense

alternate with the tentacles.

with
is

furnished

gonads, each one

inter-radial

with

pit.

outward

turned

from eight

short gastric cirri and a well developed sub-genital

a wide lenticular space at the centre of the disk.

surrounded by

three-quarters as

concave side

its

formation.

to

twelve

The stomach

is

It gives rise to sixteen

radial pockets

which extend outward, eight

sense organs.

These pockets are entirely separated each from each, and there

is

no ring

There

canal.

is

to the tentacles

and eight

to the

a well developed set of circular muscles in the

sub-umbrella, and also a powerful radial set of sixteen muscle strands which
alternate in position with the tentacles and sense organs, and extend

the septaa between the radial pockets.
radial

muscle strands

In addition to these there are sixteen

in the ex-umbrella.

tentacles and sense organs.

The

down

These extend

to the bases of the

disk and palps are of a dull amber-yellow

color and the tentacles are of a darker hue.

The nematocyst

cells

over the

ex-umbrella and the palps are orange-red, and the genital organs are of a

A

dull ochre color.

single specimen of this

medusa was found on the

face south of Rangiroa Island, Paumotus.
S"

;

September

24,

1899

;

off

Rangiroa, Paumotus Islands.

sur-


MEDUSAE.

159

Aurelia vitiana Agassiz and Mayek.
Aurelia vitiana Agassiz and Maykk, 1899;

Mus. Comp.

Bull.

XXXII.,

Zobl., Vol.

p.

171,

Plate 10, Fig. 85.

This species was very abundant upon the surface during the afternoon

hours in Neiafu Harbor, Vavau Island, Tonga, on December 5 and

None were
Fiji, in

We

be seen in the morning.

to

December, 1897

but here

;

it

found

was very calm while we were

come

also in

1899.

Suva Harbor,

appeared during the early morning

hours, and then only on perfectly calm days.
it

it

6,

in Neiafu

It

interesting that although

is

Harbor, yet the medusa? did not

morning, but swarmed there during the afternoon.

to the surface in the

SIPHONOPHORE!.
Porpita pacifica
Porpita pacifica Lesson, R.
Figs.

P.,

1830

Voy. de

;

Lesson.

la " Coquille," Zool.,

Tom.

2,

Zoophytes,

PI. 7,

3, 3'.

This species

The general

is

widely distributed over the tropical belt of the Pacific.

pneumatocyst and

color of the

more yellowish than
S"; Station 7;
"
S< (
13;
"

September

31;

S ';
1

1,

1899; N. Lat. 18°
"
9°
"

19',

W.

Long. 134°

57'.

57',

"

137° 47'.

"

S. Lat. 12° 20',

"

144°

"

off

"

5,

"

19,
1 7,

25,

"

November
December

S";

not so gray but

in Lesson's figure.

;

S'';

pol_ypit.es is

15'.

Bora Bora Island, Society Islands.
Lagoon of Funafuti Atoll, Ellice Islands.

"Velella pacifica Eschscholtz.
Velella pacifica Eschscholtz, F., 1829
Sd

S

;

rf
;

Station 14

;

September

7,

November

16,

;

Syst. der Acalephen.

1899; N. Lat. 6°
"

Tahaa

41',

W.

Long. 137°.

Island, Society Islands.


EXPEDITION OF THE "ALBATROSS,"

160

1899-1900.

DIPHYOPSIS APPENDICULATA.
ERS^EA APPENDICULATA.
Diphyopsis appendiculata Agassiz

and Mater.

Diphyes appendiculata Eschscholtz, F., 1829; Syst. der Acalephen, p. 138, Taf. XII., Fig.
Diphyes appendiculata Huxley, T. H., 1859 Oceanic Hydrozoa, p. 34, PL I., Figs. 2-2=.

7.

;

Plate 9,

This species was

W.

it

hit.

17° 32',

continued to be abundant throughout the tropical

In the Pacific species the entoderm of the polypites

regions of the Pacific.

and nematocyst batteries
in the Atlantic

38, 39.

obtained by the "Albatross" in N.

first

long. 135° 40', and

figs.

milky, or slightly yellow or pink in color, while

is

form the potypites are of a more or

green and

less intense

the nematocyst batteries of the tentacles are yellow or orange (see Bull.

Mus. Comp. Zool., Vol. XXXVII., No.

important difference between the two species
Pacific

a

manubrium within

Pacific form, therefore,

to the

more

the fact that in the

swimming-bell
it

;

possesses a

while in the Atlantic form

manubrium within

form belongs

a Diphyopsis, while the Atlantic

is

its bell.

genus Diphyes.

The animal
is

its

belongs to the genus Eudoxia, for

The

lies in

still

form the monogastric sexual generation belongs to the genus Erssea,

and lacks
it

A

34, Fig. 114).

2, PI.

somewhat

18-20 mm.

in

its

cavity

is

The

oil

anterior bell

angular and

is

There are two ascending, curved

voluminous.

and a simple circular

narrow and contains an "

and the anterior swimrnins;-bell

lens;th,

larger than the posterior.

pyramidal and
radial canals

is

The phyllocyst

vessel.

globule " near

its distal

is

extremity.

long and

There

is

a moderately deep conical hydrcecium upon the ventral face of the anterior

Hectophore, and the siphosome arises from

dage of the siphosome
This

is

is

somewhat smaller than the anterior
Indeed the siphosome

the covering tooth.

lies

side

bell,

The

first

appen-

s,

and a deep groove covered

upon which the siphosome

within this groove and

The second appendage

auxiliary swimming-bell («

cluster of

inner apex.

the large posterior swimming-bell (ps, Fig. 39).

by a projecting tooth runs down the
ated.

its

Fig. 39).

of the

protected

is

siphosome

Immediately below

is situ-

is

this

by

the small

comes a

immature feeding polypites, the older ones being successively


MEDUSA.
lower down the siphosome.
poly"pites,

The

tentacles

161

bud out from the

and then come the bracts which protect them.

the siphosome are separated by free internodes.

appendiculata, each unit

is

provided with a covering

and immature swimming-bell.

When

The

sides of the

units

upon

set free as Ersoea

scale, polypite, tentacle,