CLASS III. — GASTEROPODA. xlix 



ORDER IV. — Tectibranchiata — Monopleurobranchiata, 



Blain, 



Gills like leaflets, on the right side, or on the back. 



Genus. Subgenus. Example of Species, 



I. Pleurobranchus, Cuv Pleur. Peronii, Cuv. 



II. Pleurobranchsea, Meckel Pleur. Meckellii, Lam. 



III. Aplysia, Lin Apl. fasciata, Poiret 



IV. Dolabella, Lam Dol. Rumphii, Cuv. 



V. Notarchus, Cuv. . Not. gelatinosus, Cuv. 



VI. Bursatella, Blain Burs. Leachii, Blain. 



VII. Akera, Miiller./ 3, Akera, Cm. 



f 1. Bulleea, Lam Bull, aperta, Lam. 



1 2. Bulla, La7n Bui. lignaria, Lin. 



.<3. 



<' 3. Akera, Cuv. Dori-^ 



i dium, Meek. Lo- > Bulla carnosa, Cuv. 



V. baria, Blain .... J 



VIII. Gastropteron, Meckel Gast. Meckelii, Kosse 



IX. Gastroplax, Blain. Umbrella, Lam. 



ORDER v.— HeterOpoda. — 



In this order, the foot is formed into a vertical muscular lamina, 

 and does not form a disk, as in the other orders. 



Genus. Subgenus. Example of Species. 



!l. Carinaria, Lam Car. cymbium, Lam. 



2. Atlanta, Lesueur. . . .At. Peronii, Lesueur 



3. Firola, Peron Pter. coronata, Forskal 



4. Timorienna, Quoy.\ 



& Gaym / 



5. Monophora, Peron . . 



II. Phylliroe 



ORDER VI. — Pectinibranchiata. 



In this numerous order, the gills are pectinated, and occupy the 

 last whorl of the shell. 



