EEPOET OX THE THXICATA. 
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spicules. A few bladder cells are present in some parts of the test. The spicules are 
large and rather irregular in shape. They are mostly stellate, but the rays are often of 
different sizes and of irregular form. 
The Mantle is strong. Both longitudinal and transverse bands are present. 
The Branchial Sac has four rows of small stigmata. The transverse vessels are 
wide, and have muscle fibres. 
The Tentacles are numerous, they are of two sizes, and are placed alternately. 
Locality . — Station 142, December 18, 1873; lat. 35° 4' S., long. 18° 37' E.; depth, 
150 fathoms ; bottom, green sand ; bottom temperature, 47° F. 
Several small colonies of this species were dredged at Station 142, to the south of 
the Cape of Good Hope; the two largest are figured (PL XXXIX. figs. 12, 13). They 
are of irregular form and are attached to worm tubes, Polyzoa, and other objects which 
they have grown completely around. The colonies are of considerable thickness for their 
size. They are quite opacjue, and are of a warm grey colour with a slight yellowish 
tinge in places. 
The Ascidiozooids show externally as small circular lighter coloured dots (PI. XXXIX. 
figs. 12, 13) less than 0'5 mm. in diameter. The common cloaca! apertures are slit-like, 
and are rather more than 1 mm. in length. 
The test cells are unusually large and conspicuous. They are mostly of rounded 
forms and are very granular. The spicules are irregular in shaj^e, size, and distribution 
(PI. XXXIX. fig. 15). As a rule, however, they are more abundant in the surface layer 
of test than deeper down. They are not arranged so as to mark out Ascidiozooid areas 
as they are in Leptoclinuni tcnue and some other sj^ecies. The spicules even in the 
surface layer of the test are not so numerous as they are in most colonies of the 
Didemnidse. 
The branchial sac is fairly large. At its posterior end there is a part of its wall 
lying behind the fourth row of stigmata, and about equal to two rows of stigmata 
in breadth, which is not pierced by any apertures (PI. XXXIX. fig, 14). The stigmata 
are short, some of them are nearly circular, and they are sometimes placed irregularly. 
The ciliated cells are distinct. The muscle bands in the transverse vessels are unusually 
strong (PI. XXXIX. fig. 14, tr.). There are usually eleven or twelve stigmata in the 
widest row. In one sac examined there were five rows on each side, but some of the 
stigmata were irregular. The branchial siphon is small, but the sphincter is fairly strong. 
The endostyle is long and narrow. Its course is straight (PI. XXXIX. fig. 14, en.) 
The tentacles are rather large and numerous. 
The alimentary canal is moderately large. It forms a long narrow loop. The 
stomach is small. The rectum contains dark-coloured faecal pellets. It crosses the 
abdomen and lower part of the thorax obliquely from the ventral to the dorsal edge. 
