i8o 



THE GASTROPODA 



Bergh. FAMILY 7. FIONIDAE, Alder and Hancock. Dorsal tegumentary 

 papillae provided with a membranous expansion ; liver in the form of 

 two longitudinal canals into which the caeca of the dorsal papillae open ; 

 male and female orifices at some distance from one another ; pelagic. 



B 



FIG. 167. 



Pleurophyllidia liiieata. A, dorsal view ; B, 

 ventral view, b, the mouth ; /, lamelliform 

 pallial gills (the posterior part of the foot bears 

 a median glandular tract). (From Lankester, 

 after Souleyet.) 



FIG. 168. 



Hedyle glandullfera, dorsal aspect, e, 

 eye ; /, foot (posterior part) ; n.s, nervous 

 system ; ph, pharynx ; sp, spicula ; v.m, 

 visceral mass. (After Kowalewsky.) 



Fio. 169. 



Pseudowrmis paradoxits, 

 dorsal aspect, a, anus ; ni, 

 cuidosac ; e, eye ; k, kidney ; 

 J, liver ; m, mouth (on the 

 ventral side, seen through 

 the transparent head) ; n.s, 

 nervous system ; of, oto- 

 cyst ; ph, pharynx ; st, 

 stomach. (After Kowalew- 

 sky.) 



Genus Fiona, Hancock and Embleton. FAMILY 8. PLEUROPHYLLIDIDAE, 

 Adams. Anterior tentacles in the form of a digging shield ; mantle 

 naked ; tegumentary papillae or " branchiae " situated along the sides of 

 the foot, beneath the mantle border. Genus Pleurophyllidia, Meek el 

 (Fig. 167). FAMILY 9. DERMATOBRANCHIDAE, Fischer. Like Pleura- 



