400 



MOLLUSCA. 



Fam. 24. Chenopodidae (Aporrhaidae). Foot elongated, narrow; proboscis 

 short, tentacles long; siphon short. Shell like that of S trombus. Chenopus 

 Philippi (Aporrhais Aldrovandus) . 



Fam. 25. Struthiolariidae. Shell buccinoid ; operculum claw-shaped, 

 notched; foot broad and short. Struthiolaria Lara. 



Fam. 26. Cypraeidae. Cowries. Mantle reflected over the shell, and 

 provided with appendages ; shell convolute, enamelled ; spire concealed ; outer 

 lip thickened, inflected; operculum absent. The young shell has a prominent 

 spire. Cypraea L. , Cowry ; Erato Risso ; OvulalSmg. ; Pustularia Swainson. 



Fam. 27. Doliidae. Shell ventricose, spirally furrowed; no operculum; 

 eyes stalked; foot large and expanded ; ^iphon long. Dolium Lam., the Tun; 

 Pyrula (Pirula) Lam., fig-shell. 



Fam. 28. Cassididae. Shell ventricose with varices, spire short, outer lip 

 reflected or thickened, operculum semilunar ; eyes sessile ; foot large, rounded in 

 front; proboscis and siphon long. Cassis Lam., helmet -shell (Fig. 314); 

 Cassidaria Lam. 



Fam. 29. Tritonidae. A proboscis; siphon well developed but short; foot 

 short; shell thick, varicose, outer lip inflected and thickened, operculum 

 corneous ; periostracum often thick and hairy. Triton Lam. ; Raiulla Lam. 

 frog-shell. The genus Oocorys Fischer, is allied here. 



TV " 



FIG. 315. Male of Carinaria mediterranea (after Souleyet, Gegenbaur, and Keferstein). A anus ; 

 Ar anterior aorta ; At auricle ; EG buccal ganglion; Bm buccal mass; Br gills ; CG cerebral 

 ganglion ; F flagellum ; L liver ; M crop ; Mg mantle ganglion ; N kidney ; mouth ; Oc 

 eye ; Ot otocyst ; p pro- and mesopodium ; Pe penis ; Pg pedal ganglion ; S sucker ; Sp 

 salivary gland ; T testis ; Te tentacles ; Vd vas deferens ; Ve ventricle ; Wp ciliated furrow ; 

 Z posterior branch of anterior aorta. 



Section 2. Heteropoda.* 



The Heteropoda, are free-swimming, pelagic Pectinibranchiates, with laterally- 

 compressed foot, taenioglossate radula, and otocysts near the cerebral ganglia. 

 They are without jaws. 



* C. Gegenbaur, " Untersucli. ub. Pteropoden u. Heteropoden," Leipzig, 1854. 

 T. H. Huxley, "On the Morphology of the Cephalous Mollusca," etc., Phil. 

 Travis. 1853. 



