132 LIVERPOOL BIOLOGICAL SOCIETY. 
number of short unbranched filaments are present. The 
branchial and atrial apertures are shght prominences. 
In external appearance (Pl. XIIL., fig. 1) this species is 
not unlike Polycarpa comata, with which it has, however, 
no close relationship. The body when removed from the 
test 1s of rounded outline. The left reproductive mass, 
nearly enclosed in the very long curved intestine, is seen 
on the left side (Pl. XIII., fig. 2, g.); while the other 
reproductive mass, the renal organ and the heart, lie upon 
the right side of the body. 
In possessing only five folds on each side of the 
branchial sac, this species differs from most members of 
the genus Molgula and agrees with Molgula (Pera) chrys- 
tallina,* Moller, from which species, however, it differs 
totally in external appearance and in the condition of 
the test. 
The dorsal tubercle (Pl. XIII., fig. 6) is in that in- 
teresting, simple condition which I first describedt in the 
cases of Molgula pyriformis and Eugyra kerguelenensis, 
and which has since been found in the case of several other 
species. 
The alimentary canal is very long, and is closely folded 
upon itself throughout the whole length (Pl. XIII., fig. 
2,7.). The stomach is very far forward, and the double 
intestinal loop is bent ventrally anteriorly and then 
dorsally. 
* For a description of this species see Traustedt, Vid. Medd. Nat. For. 
Kopenhagen, 1879-80, p. 27; and fora figure see Verrill, Amer. Jour. Se. and 
Arts, 1872, pl. viii., fig. 9. 
+ Zool. Chall. Exped., Report on Tunicata, part i., pp. 79 and 81, pl. vi 
figs. 3 and 9. 
