REPORT Ois’ THE THNICATA. 
221 
inwards to form slight horizontal membranes projecting between the rows of stigmata 
(PL XXIX. fig. 3, h.m.). 
The endostyle is large and conspicuons (PI. XXIX. fig. 4, en.). Its course is very 
undulating. The dorsal langnets are large and closely placed. 
The oesophagus is a long narrow curved tube with the convexity dorsal (PI. XXIX. 
fig. 4, ce.). The stomach is not large; its shape is almost spherical. The wall is thick, 
and is folded longitudinally; the folds are especially prominent at the anterior end 
(PI. XXIX. fig. 4, St.). The intestine is narrow in its first part, which runs posteriorly 
from the stomach. It usually becomes dilated (see PI. XXIX. fig. 4, i.) just at its most 
posterior part before turning ventraUy and anteriorly to pass into the rectum ; the 
intestinal loop is narrow. The rectum is a long wide thin-waUed tube running up the 
ventral edge of the abdomen and thorax (PI. XXIX. fig. 4, r.). It is usually filled with 
dark-coloured faecal matter, and is just visible to the unaided eye in making a dissection 
of the colony. 
The post-abdomen (PI. XXIX. fig. 4, p.abd.) has its edges very irregular, and usually 
sacculated in appearance. The spermatic vesicles are spherical in shape, and have each 
a fine duct which runs to the lower end of the vas deferens (PI. XXIX. figs. 4 and 5, 
tv. and v.d.). They stain a deep red colour with picrocarmine. The vas deferens is 
large and conspicuous, and of great length. The ducts from the vesicles are all attached 
along one side of it (PI. XXIX. fig. 5). The ova are of a bright yellow colour. They 
are placed in the anterior part of the post-abdomen. 
The lower end of the post-abdomen is usually somewhat swollen (PI. XXIX. fig. 4, v.ap'), 
and it gives off two or three very short esecal j^rocesses which are evidently rudimentary 
vascular appendages. 
Amaroucium complanatum, n. sp. (PI. XXX. figs. 16-17). 
The Colony has the form of an ovate or pyriform mass attached by one end and 
much compressed laterally. The upper end is broad and rounded, but thin. The surface 
is rather uneven. The colour is a light grey. 
The length is 3 cm., the breadth is 2 cm., and the thickness 5 mm. 
The Ascidiozooids are fairly large and numerous. They are greatly elongated antero- 
posteriorly, and are placed vertically in the colony. The body varies from 5 mm. to 
1 cm. in length, and is less than 1 mm. in breadth. It is not divided into regions 
externally. 
The Test is firm and rather tough. It is of a light grey colour and is moderately 
transparent. The clear matrix is crowded with test cells which are small but very 
numerous. Most of them are of rounded form, and some are very granular. No 
pigmented cells and no bladder cells are present. 
