Fig. 4. 
on the Natural Group of Tunicata. 553 
Anal orifice. 
Branchial orifice. 
Envelope. 
Right ovary, lying between stomach and bran- 
chial pouch. 
AOD 
d. Oviduct of same, opening towards anal orifice. 
k. Left ovary, terminating upwards in a neck. 
O. Œsophagus, or that extremity of the intestinal 
canal which communicates with the branchial 
pouch. 
S. Stomach. 
H. Anus. 
V. Heart. 
D. Dorsal sulcus. 
o. Lateral orifice, communicating by a tube ¢, with 
a diaphanous pouch p, containing one or two 
blackish nodules n. 
Cystingia Griffithsii much magnified as before, but having 
the whole of the right side of the envelope removed, and 
the stomach thrown further back, in order to show the 
- branchial pouch, which appears communicating by a 
narrow neck with the branchial orifice. The left ovary 
is hid by the enormous stomach, but in other respects 
the parts are nearly in the same situation as in the former 
figure. 
5. Heart of Cystingia Griffithsii (magnified), having the se- 
cond of its four vertical apertures stretched open. 
. The heart and other parts on the right side of Cystingia 
Griffithsii lifted up, to show the oviduct of the left ovary 
opening downwards to the anal orifice, round which we 
observe a net-work of muscular fibres reticulating on the 
mantle. 
TAB. 
