^^-pten. 



cer.-- 



Fig- 389. Opisthobranchiate molluscs, in dorsal view. A, Aplysia, with 

 parapodia {par.) turned to the side to show the mantle cavity; nervous system 

 and buccal mass indicated by dotted lines. B, Doris, with position of heart 

 indicated beneath the mantle. C, Eolis. After Alder and Hancock. C, One 

 of the cerata of Eolis, shown in section, c.c. ciliated canal communicating 

 with hcp.c. the hepatic caecum, a diverticulum of the intestine; c.s. cnidosac, 

 opening to the exterior and containing numerous nematocysts ingested in its 

 cells. D, Cavolinia with alimentary canal (a/.) seen through the transparent 

 tissues and the direction of the ciliated currents on the epipodia indicated 

 by arrows. After Yonge. Other letters: a/, alimentary canal; an. anus; an. 

 auricle ; ce.g. cerebral ganglion ; cer. cerata ; ct. ctenidium ; epi. epipodia ; 

 2 op. genital aperture; op.s. opening of shell sac; p. penis; pa.g. parietal, 

 pl.g. pleural, ped.g. pedal ganglia; par. parapodia; sem.gr. seminal groove; 

 ten. tentacles; vis.g. visceral ganglion; M. mouth; ven. ventricle. 



