1 84 



THE ASCWIANS. 



at.s-.. 



an 1 



I^'ig- 94- — Diagram of a dissection of Ascuiia, from the right side. (After 

 Herdman.) 



The peribranchial cavity is indicated by the black shading. 



ayi. Anus. at.s. Atrial siphon, c.^. Cerebral ganglion, beneath which is the 

 subneural gland and its duct. dj. Dorsal lamina, end. Endostyle. ^. Gonad. 

 ^.d. Genital duct. i/it. Intestine. ;//. Muscular mantle, oes. Aperture, leading 

 from branchial sac into oesophagus, or.s. Buccal siphon, ph. Branchial sac. 

 St. Stomach. /. Test or cellulose mantle, tn. Buccal or coronary tentacles. 

 ty. Typhlosole ; internal fold of intestinal wall, to increase the digestive surface. 



