CLASS III. — GASTEROPODA. 
xlix 
ORDER IV . — Tectibranchiata — Monopletjrobranchiata, 
Blain . 
Gills like leaflets, on the right side, or on the back. 
Genus. Subgenus. Example of Species. 
I. P leurobranchus, Cuv Pleur. Peronii, Cuv. 
II. P leurobranchaea, Meckel pi eur . 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. 
f 1 . Bullaea, Lam Bull, aperta, Lam. 
i2. Bulla, Lam Bui. lignaria, Lin. 
VII. Akera, Muller, f 3. Akera, Cuv. Dori-^ 
k dium, Meek. Lo- V Bulla carnosa, Cuv. 
baria, Blain....) 
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. 
I. Ptero trachea, 
Forsk 
IT. Phylliroe 
Subgenus. Example of Species. 
! 1. Carinaria, Lam Car. cymbium, Lam. 
2. Atlanta, Lesueur . . . . At. Peronii, Lesueur 
3. Firola, Peron Pter. coronata, Forskal 
4. Timorienna, Quoy.\ 
& Gaym / 
5. Monophora, Peron . . 
ORDER VI. — Pectinibranchiata. 
In this numerous order, the gills are pectinated, and occupy the 
last whorl of the shell. 
