REPOET ON THE THNICATA. 
115 
The alimentary canal is comparatively inconspicuous, and is usually more or less 
hidden by the reproductive organs (PI. XIY. fig. 5). The oesophagus (ce.) commences 
rather at the dorsal side of the posterior end of the branchial sac, and leads directly 
backward in a funnel-like form (PL XIV. fig. 6, ce.) to the anterior end of the stomach. 
The stomach is not large, and seems to vary a httle in its exact shape. In some cases 
(PI. XIY. fi g. 5, st.) it is elliptical with narrow ends, which pass gradually the one into 
the cesophagTis and the other into the intestine, but in one Ascidiozooicl examined the 
stomach was truncated at the anterior end and the funnel-shaped oesophagus entered it 
in a slight depression (see PI. XIY. fig. 6, st.). The stomach w'^as long and nearly equally 
wide throughout its anterior three-fourths, which was directed dorsally and posteriorly. 
The remaining fourth narrowed rapidly, and turned abruptly so as to form a right angle 
with the front part and point ventraUy and posteriorly. The posterior end was only 
about half as wide as the anterior, and narrower than the intestine (PI. XIY. fig. 6, ^). 
The intestine is in all cases a rather narrow tube, which runs posteriorly and then 
ventrally, and turns anteriorly with a wide curve leaYng an open loop (PI. XIY. fig. 5). 
It crosses close to the anterior end of the oesophagus, and then becomes the rectum, 
which is continued up the dorsal edge of the branchial sac towards the atrial aperture. 
The genital glands are very large, but in all the Ascidiozooids examined consist of the 
male system only. There are a number of large ovate and pyriform seminal vesicles, 
forming together a mass about four times as large as the stomach (PI. XIY. fig. 5, g.). 
They fill up the greater part of the intestinal loop, and project beyond the intestine 
posteriorly and ventrally for a considerable distance. Thus the posterior half or so of the 
visceral mass is usually formed by the reproductive organs. Each seminal vesicle has a 
short narrow duct, and the various ducts join to form a very large vas deferens, which 
leaves the mass at its posterior end (PL XIY. fig. 5, v.d.), and, curving round ventrally 
and then anteriorly, forms the ventral border of the greater part of the visceral mass. 
Eventually the vas deferens reaches the rectum, along with which it crosses the base of 
the branchial sac to reach its dorsal edge. In the whole of its course the vas deferens is 
a most conspicuous object. It is usually nearly as wide as the intestine (see PL XIV. 
fig. 5), and takes up stain very readily. 
Colella murrayi, n. sp. (PL XYII. figs. 1-11). 
The Colony is rudely club-shaped, consisting of a large expanded head supported 
l)y a short stout peduncle. The head is longer than it is broad, and is flattened 
laterally. The upper end is wide, and has an unevenly truncated appearance. The highest 
point is in the middle. The lower end tapers into the peduncle. The sides of the head 
are nearly straight. The peduncle is shorter than the head, and is not flattened laterally. 
It is not wide relatively to the head, but is strong. The surface is even, and fairly smooth. 
