328 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



condition might be effected without passing through a stage 

 like Ciona, I do not believe that it represents such a 

 transitional condition, for the curve of the intestine is 

 exactly like that of Corella. Furthermore, the position of 

 the heart, which in C. -productum is on the side of the 

 stomach farthest from the midventral line, still more 

 increases this similarity. As the general course of the 

 digestive tract in our species is exactly like that of C . mac- 

 leayanum a detailed description is unnecessary. 



The epithelium of the ventral wall of the stomach is 

 thrown into folds forming a deep groove which extends 

 from the entrance of the oesophagus to the exit of the intes- 

 tine. From the outside these appear as a series of longitu- 

 dinal lines that have often been described. The rest of the 

 stomach has its surface area increased by the formation of 

 pocket-like projections which give it a very characteristic 

 appearance in the surface view (fig. 14). A reticulate 

 gland with a single duct opening into the stomach covers 

 its pyloric portion and the adjacent intestine. This gland 

 presents all the features of the one described by Winiwarter 

 (1895), except the large number of separate ducts. The 

 intestine is quite simple and does not possess a typhlosole. 



The sexual organs are much like those described for C. 

 macleayanum by Wagner. Both ovary and testis are a 

 complicated system of dichotomously branching tubes 

 which never reunite. They extend both ventrally and dor- 

 sally to the digestive tract, and in the older individuals, 

 with the assistance of the pyloric gland, they completely 

 cover it. Their ducts follow the course of the intestine 

 and open in the immediate vicinity of the anus. Figure 

 14 represents these organs in a young animal. 



Conclusion. 



This account of the structure of Chclyosoma shows that it 

 is even more closely related to Corella than was formerly 

 supposed. In fact, it agrees with Corella in all the char- 

 acters which differentiate the latter from Ascidia. On the 



