I915.] A. OKA : The Tunicata of the Indian Museum. 29 
first recorded from Banda. They are much contracted, and it was difficult to make 
out their internal structure. The external appearance, however, and the greater 
part of what could be examined internally agree pretty well with the description 
given by Sluiter. The slight differences which occur here and there may be 
regarded as coming within the limits of individual variation. I insert here a brief 
account of one of the specimens which was least contracted. 
The body is cylindrical in shape, about 15 mm. long and 5 mm. across, with 
the posterior end tapering into a short stalk. The branchial aperture is anterior 
and terminal, the atrial is placed a little backwards on the dorsal median line; the 
two are borne on short conical projections, and are not lobed. The surface is of a grey 
colour, and is wrinkled transversely in consequence of preservation. The test is 
thin, soft, and transparent. The branchial sac is regularly built but rather small; 
there are broad horizontal membranes running along the transverse vessels and the 
stigmata are long and narrow. Internal longitudinal bars are entirely absent. The 
dorsal tubercle and dorsal lamina are just like the figures given by Sluiter. The 
intestine forms a distinct abdomen; the stomach is large, oval and smooth-walled. 
The gonads are situated in the intestinal loop and are visible on both sides, and the 
duct is seen running parallel with the terminal portion of the intestine. Four 
tadpoles were found in the atrial cavity. 
PELAGIC FORMS. 
Of the three different groups comprised in the Pelagic Tunicata each is repre- 
sented by a single family in the collection,—the Ascidiae Salpaeformes by the family 
Pyrosomatidae, the Thaliacea by the family Salpidae, and the Larvacea by the 
family Appendiculariidae. 
Fam. PVROSOMATIDAE. 
The collection contains numerous specimens of Pyrosoma, but they are mostly 
in such a bad state of preservation that it is almost impossible to determine to what 
species they belong. It is even difficult to count how many colonies there are, as 
the specimens are nearly all very incomplete fragments, some being not more than 
one-tenth of a colony. The only species which I could identify with some degree of 
certainty is the following. 
Pyrosoma spinosum, Herdman. 
Pyrosoma spinosum, Herdman, Report on the Tunicata, Part III. Report of the Scientific Results 
of the Voyage of H.M.S. “‘ Challenger,’’? Vol. XXVII, 1888. 
Localities. (1) Laccadive Sea, at Station 275, 8° 27’ N., 75° 35’ E. ; depth of 
net 731-771 fathoms; bottom green mud. One colony, 80 mm. long and 15 mm. 
across. (2) 20° 17’ 30” N., 88° 50’ E. Two imperfect colonies. (3) No locality 
given, 1300 fathoms. Two imperfect colonies. 
Specimens of Pyrosoma from the following localities could not be identified on 
account of their bad state of preservation :— 
