EEPORT ON THE TUNICATA. 
227 
a free rounded projection (PL XXX. fig. 9). The upper surface was probably more 
perfectly convex in the h\dng condition than it is now. 
The Ascidiozooids modify the colour of the colony considerably, on account of their size 
and the transparency of the test. They are scattered irregularly over the colony, and lie 
at various angles to the upper surface. The anterior part of the body is of considerable 
breadth, but there is no external line of demarcation between the thorax and the abdomen. 
The test is very compact, and is cartilaginous in consistence; it appears perfectly clear 
and homogeneous in sections. The test cells are much more numerous in some places than 
in others. Many of them are fusiform and very much elongated. 
Some parts of the mantle are very strong, the musculature forming almost a continuous 
layer. The sphincter at the branchial aperture is strong. 
The branchial sac is very opaque, and is in a lowly developed condition, the stigmata, 
being small and the ciliated cells inconspicuous. The transverse vessels are provided with 
horizontal membranes (PI. XXX. fig. 10, li.m.). The endostyle is larger and more 
conspicuous than usual. It occupies a considerable part of the ventral half of the thorax. 
The tentacles are stout but not very long. There are about twenty, ten longer and 
ten shorter. The dorsal tubercle is rather large. The nerve ganglion, which is placed 
immediately behind the dorsal tubercle, is very large, and is nearly circular in outline. 
The abdominal part of the body is relatively small, and the alimentary canal forms a 
short loop. The stomach has its wall folded longitudinally. The reproductive organs 
occupy the large post-abdomen. The vas deferens is very wide and is a conspicuous object 
in its entire length. 
O 
In some of the Ascidiozooids tailed larvae were found. They are large, have a 
moderately elongated body, vith very distinct pigmented sense-organs placed about 
two-thirds of the way back. The anterior end is rather broader than the posterior 
(PI. XXX. fig. 11). 
Amaroucium recumbens, n. sp. (PI. XXIX. figs. 13-15). 
The Colony is of shghtly elongated form and is attached by the whole of one side to 
a fragment of shell. The upper one-third is wider than the lower part, and the top is 
rounded. The lower end is prolonged on one side to form a thin expansion attached to 
the shell. The surface is moderately smooth. The colour is light grey, becoming rather 
darker towards the lower end. 
The length is 2 ‘5 cm., the greatest breadth is 1'2 cm., the breadth of the lower 
narrower part is 6 mm., and the greatest thickness is 8 mm. 
The Aseidiozooids are rather small, and are not numerous. They seem to be scattered 
irregularly over the upper part of the colony. The usual length is about 4 mm. 
and the greatest breadth is less than 1 mm. The thorax is relatively large, being 
