238 CALIFORNIA ACADEMY OF SCIENCES. 



in the lining epithelium as in the inter-vascular cell tissue. 

 As in Gordiodrilus, the nuclei are less in number than 

 the cells and of unusually large size for so narrow cells. 

 At the entrance of the narrow part connecting the pouch 

 with the tubular intestine the epithelial lining is thicker 

 than in the main cavity of the pouch. In one specimen 

 the left pouch was forked and a lateral vascular trunk 

 issued from each pouch, but on account of the nature of 

 the section I could not follow its course forward. 



The pouch is supported by a heavy muscular band 

 which attaches to the center of the convex or outer part 

 of the pouch and thence runs through the posterior sep- 

 tum connecting with the parietes of somite x. 



The position of the pouch on somite ix appears en- 

 tirely constant, none of the 10 species known differing in 

 this respect. With the pulsating of the bloodvessels the 

 pouch expands or contracts following the same beat as 

 the hearts. In alcoholic specimens the pouch may be 

 more or less contracted in the same species. There is no 

 gizzard and no typhlosole. 



The tubular intestine which extends from the pouch 

 in somite ix to the sacculated intestine in the xii re- 

 sembles (fig. 19), greatly the oesophagus in form. It is 

 tubular, neither wider nor narrower and its inner epithe- 

 lial hning is strongly ciliated. At the junction with the 

 sacculated intestine it is sometimes slightly contracted, 

 but there is no real narrowing of the tube as indicated in 

 Beddard's figure of Ocnerodrilus Eiseni, nor is there any 

 swelling at the junction of the diverticula as in that 

 species. The vessel furnishing the blood for the diverti- 

 cula first enters the tubular intestine from the hearts. 



In O. Rosce the oesophagus and tubular intestine are 

 much nipped by the septa and enlarged at the diverticulum 

 entrance, more so than in most other species, but not to 



