SANDER RANG. 581 



Fam. 2. Semi-Phyllidiens, Lamarck. Genera — 



Ancyllus, Pleurobranchaaa, Pleurobranchus, Um- 

 brella, Spiricella, Siphonaria. 

 Order IV. Tectibranciies, Cuvier. 



Fam. 1. Aplysiens, Blainville. Genera — Aplysia, 



Bursatella, Actaeon. 

 Fam. 2. Aceres, Cuvier. Genera — Akera, Bulla, 



Gasteropteron, Sormetus. 

 Order V. 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. 

 t A membranous appendage to introduce the loater into the 

 branchicB. 



Fam. 1. Turbines, Ferussac. Genera — Paludina, 



Turritella, Proto, Vermetus, Siliquaria, Magilus, 



Valvata, Natica. 

 Fam. 2. Trochoides, Cuvier. Genera — Navicella, 



Nerita, Ampullaria, Iantliina, Litiopa, Phasianella, 



Trochus, Pleurotomaria, Scalaria, Melanopsis, 



Planaxis. 

 ■f-f A siphon to introduce the water to the branchice. 



Fam. 3. Cerites, Ferussac. Genus — Cerithium. 

 Fam. 4. Pourpres, Adanson. Genera — Buccinum, 



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



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



lombella, Turbinella, Pyrula, Fasciolaria, Fusus, 



Pleurotoma, Rostellaria. 

 Fam. 5. Strombes, Ferussac. Genus — Strombus. 

 Fam. 6. Cones, Ferussac. Genera — Conus, Su- 



bula. 

 Fain. 7. Enboules, Lamarck. Genera — Terebra, 



Mitra, Terebellum, Ancillaria, Oliva, Cypraea, 



Ovula, Volvaria, Marginella. 



