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TUNICATA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 315 
for an Ascidia. ‘The branchial sac is also thick, and both mantle and branchial sac are 
of a distinctly pinkish colour which may be the remains of the orange-red that SLUITER 
records. There are twelve moderate-sized tentacles, and the horse-shoe shaped dorsal 
tubercle is very large, reaching up to the base of the tentacles. It seems larger than in 
SLUITER’S specimens, in which, however, the dorsal tubercle is recorded as being rather 
variable. 
SLUITER states that no teeth are present on the dorsal lamina; but I find that in 
the Scotia specimen the dorsal lamina has marked denticulations along its free edge, 
amounting in-one part to short tentacular languets. But still I have no doubt that 
my specimen belongs to SiuirEr’s species, and that the dorsal lamina must be regarded 
as somewhat variable in character. The viscera on the left side of the body are 
unusually large and opaque. 
Family Distomips. 
Colella pedunculata (Quoy and Gaimard). 
? Sycozoa siytllinoides, Lesson. 
t Colella tenuicaulis, Herdman. 
? Colella umbellata, Michaelsen. 
One colony having a stalk bifurcated near the top and bearing two “heads” was 
found at Station 346 on Burdwood Bank, 56 fathoms, on December 1, 1908, and presents 
to some extent characters recalling all the species named above. In the branching of 
the peduncle it is like MicHaELsen’s C. wmbellata from the Falklands; in the general 
appearance of the ‘‘ head,” however, it is more like Quoy and Gaimarp’s C. pedunculata, 
found by the Challenger at the Straits of Magellan, the Falkland Islands, Kerguelen, 
ete. The long slender stalk recalls the Australian C. tenuicaulis; and it is possible 
that Lrsson’s Sycozou sigillinoides may be identical with one or more of these other 
named forms. Both the “heads” are, unfortunately, in the single colony in a very 
ragged condition—possibly dead when collected—so that the more minute characters 
of the Ascidiozooids cannot be determined. 
Holozoa cylindrica, Lesson. (Plate, fig 2.) 
(2) ignotus, Herdman, Challenger Report, i1., 1886, p. 251. 
Julinia australis, Calman, Quart. J. Micr. Sci., 1894, p. 1. 
Distaplia ignota, Herdman, Report on “Southern Cross” Tunicata, Brit. Mus., 1902, p. 197. 
Holozoa cylindrica, Less.—Hartmeyer, in Bronn’s Tier-Reichs, “Tunicata,” 1909. 
This large and apparently abundant Antarctic species was obtained by the Scotia 
Expedition at the following localities :— 
I. Station 346, Burdwood Bank, 56 fathoms, December 1, 1903. Seventeen 
fragments from 10 to 30 cm. in length by 2 to 4 cm. in diameter. All 
in bad condition, soft and partly macerated, with many other animals, 
Hydroids, Polyzoa, ete., entangled in the irregular, ragged surface. 
