52 
THE VOYAGE OF H.M.S. CHALLENGEE. 
equilateral triangle in side view. The dorsal end is the widest part, and has five or six 
lobes upon each side. From the grooves between these lobes the channels, corresponding 
to the ridges on the inner surface, converge towards the narrow intestinal end. On the 
anterior surface of the stomach, about two-thirds of the way from the oesophagus to the 
intestine, there is a large ovate thick-walled caecum (PI, III. fig. 21, ccb.) into which the 
duct of a gland placed on the walls of the intestine opens. Beyond this caecum the 
stomach tapers into the intestine, which turns anteriorly and dorsally, then a little 
posteriorly towards the oesophagus, and then finally curves sharply forward to become 
the short rectum. At its commencement the intestine is narrow, in its forward curve it 
widens, and then in its second or rectal bend it narrows again, and the rectum is the 
narrowest part of the alimentary canal (PI. III. fig. 21). 
The intestinal gland is composed of a number of clear tubules, which form a network 
over the last portion of the intestine. The duct springs from the posterior side of that 
region, and runs ventrally and posteriorly to open by a dilated end into the caecum on 
the anterior wall of the stomach (see PI. III. fig, 21). This system is the same as the 
so-called liver of many Tunicata, and the system in Perophora and Salpa, discussed 
by Chandelon,^ and the refringent tubules described by Giard^ in many Compound 
Ascidians, and the more posterior of the two glandular systems which I have figured in 
Doliolum.^ 
Many tailed larvae occur in some parts of the colony. They have rounded or ellipti- 
cal bodies about 0’42 mm, antero-posteriorly, and the tail measures about 0‘8 mm. in 
length. In these larvae there is only a single pigmented sense-organ present. 
Botrylloides fulgurate, n. sp. (PI. Ill, figs. 1-8). 
The Colony is a large regular spreading mass of considerable thickness. The surface 
is uneven but smooth. The colour varies from buff to light brown, and has in places a 
slight pinkish tint. The anterior ends of the Ascidiozooids form lighter areas, and the 
edges of the colony are light grey. The common cloacal apertures are inconspicuous. 
The extreme length of the colony is about 8 ’5 cm., the greatest breadth 4*5 cm., and 
the average thickness about 4 mm. 
The Ascidiozooids are elongated antero-posteriorly, and are about 3 mm. in length 
and very nearly 1 mm. in greatest breadth. The light coloured area visible on the 
surface of the colony is rather less than 1 mm. in its greatest diameter. 
The Test is rather hard, firm, and tough. It does not become excessively thickened 
in any part. There is very little expanded edge, the margins of the colony being 
comparatively thick and rounded, and of a greyish colour. The terminal knobs of the 
> Sur une annexe, &c.. Bulletin de I’Acad. Boy. de Belrique, t. xxxix., No. 6, 1875. 
2 Reclierclies sur les Synascidies, Arch, de Zool. exper., t. i. p. 536. 
3 Report upon the Tunicata collected during the Cruise of H.M.S. “ Triton,” Trans. Roy. Soc. Edin., vol. xxxii. 
pt. i. p. 93. 
