24 Memoirs of the Indian Museum. [Vor. VI, 
with the transverse vessels short curved papillae with rounded tips. Intermediate 
papillae do not occur. The meshes are longer than broad, and contain about four 
stigmata each. Owing to the contracted state of the specimen the form of the 
dorsal tubercle could not be ascertained. 
The alimentary canal forms a double loop with only a little space in the first 
loop. The stomach is globular, with irregularly raised walls, and is sharply bounded 
from the intestine. The intestine is rather thick throughout, except the rectum which 
is very short and narrowed. The gonads are not well developed: they lie in the first 
intestinal loop and seem, partly at least, to extend over the outer surface of the 
intestine. 
The locality is East Island, Andamans (coll. Dr. A. R. Anderson), 1808. 
In the same bottle with this there is a specimen of a simple Ascidian entirely 
covered with shell fragments As nothing but the test is preserved it is impossible 
to determine to what genus and species it belongs, but judging from the shape 
and condition of the test I am inclined to believe that it is Styela lapidosa, Herdman, 
first described from Ceylon. | 
Ascidia irregularis, n. sp. 
(Pl. IV, figs. 5-10.) 
External Appearance.—The body is roughly oval in outline and a little flattened 
laterally. It is attached by the entire left side. Encircling the area of attachment 
the test sends out a thin layer extending over the substratum in the form of an 
irregular skirt. The siphons are both prominent and tube-like; the branchial is 
situated at a little distance from the anterior end, and is pointed anteriorly and to 
the right ; its aperture is surrounded by seven lobes, two of which are much smaller 
than the rest. The atrial siphon is placed about half way from the anterior to the 
posterior end, and is pointed posteriorly and to the right; its aperture is only five- 
lobed. The surface is naked and shows small pointed protuberances all over, which 
causes a very rugged appearance (Pl. IV, fig. 5). The colour is a hyaline pale yellow. 
In size the animal is 29 mm. long, 20 mm. broad, and 8 mm. thick. 
The Test is thin, cartilaginous, transparent, and of a pale yellow colour. Onthe 
left side, by which the animal is attached, it is very thin and shows the internal 
viscera most clearly. 
The Mantle is very delicate on the left side, where no muscle fibres are visible. 
On the right side the musculature is pretty well developed and forms a continuous 
layer of obliquely running fibres (Pl. IV, figs. 6 and 7). 
The Tentacles are simple, filiform, with tapering ends; they are about sixteen 
in number and are all of one size. 
The Branchial Sac is delicate, and is not plicated longitudinally. ‘The transverse 
vessels are all of one size. The internal longitudinal bars are moderately strong and 
bear at the angles of the meshes, as well as in the middle of each segment, short 
conical papillae with bluntly pointed ends (Pl. IV, fig. 10). The papillae are all of 
the same form, but those at the angles of the meshes are somewhat larger than the 
