SANDER HANG. 581 



Farn. 2. SEMI-PHYLLIDIENS, Lamarck. Genera 



Ancyllus, Pleurobranchaea, Pleurobranchus, Um- 

 brella, Spiricella, Siphonaria. 

 Order IV. TECTIBRANCHES, Cuvier. 



Fam. 1. APLYSIENS, Blainville. Genera Aplysia, 



Bursatella, Actaeon. 

 Fam. 2. ACE RES, Cuvier. Genera Akera, Bulla, 



Gasteropteron, Sormetus. 

 Order Y. PULMONES INOPERCULES, Ferussac. 



Fam. 1. LIMACES, Ferussac. Genera Onchis, On- 



chidium, Limacella, Limax, Parmacellus, Testacel- 



lus. 

 Fam. 2. LIMACONS, Ferussac. Genera Vitrina, 



Helix, Vertigo, Partula. 

 Fam. 3. AURICULES, Ferussac. Genera Carychium, 



Auricula, Pedipes, Scarabus. 

 Fam. 4. LIMNEENS, Lamarck. Genera Planorbis, 



Limnaea, Physa. 

 Order VI. PULMONES OPERCULES, Ferussac. 



Fam. 1. HELICINES, Ferussac. Genus Helicina. 

 Fam. 2. TURBICINES, Ferussac. Genera Ferussina, 



Cyclostoma. 



Order VII. PECTINIBRANCHES, Cuvier. 

 f A membranous appendage to introduce the water into the 

 branchiae. 



Fam. 1. TURBINES, Ferussac. Genera Paludina, 



Turritella, Proto, Vermetus, Siliquaria, Magilus, 



Valvata, Natica. 

 Fam. 2. TROCHOIDES, Cuvier. Genera Navicella, 



Nerita, Ampullaria, lanthina, Litiopa, Phasianella, 



Trochus, Pleurotomaria, Scalaria, Melanopsis, 



Planaxis. 

 f f A siphon to introduce the water to the branching. 



Fam. 3. CERITES, Ferussac. Genus Cerithium. 

 Fam. 4. POURPRES, Adanson. Genera Buccinum, 



Harpa, Purpura, Concholepas, Nassa, Dolium, Cas- 



sidaria, Cassis, Cancellaria, Ricinula, Murex, Co- 



loinbella, Turbinella, Pyrula, Fasciolaria, Fusus, 



Pleurotoma, Rostellaria. 



Fam. 5. STROMBES, Ferussac. Genus Strombus. 

 Fam. 6. CONES, Ferussac. Genera Conus, Su- 



bula. 

 Fam. 7. ENROULS, Lamarck. Genera Terebra, 



Mitra, Terebellum, Ancillaria, Oliva, Cyprsea, 



Ovula, Volvaria, Marginella. 



