12 GASTEROPODA. 
parts of the fins and the inside of the legs) with violet-red or 
purple. The spots on the lower aspect of the sac are smaller 
and less numerous. Length from 3 to 5 inches. 
Inhabits the sea, and is most commonly found in bays and 
estuaries. 
CLASSIS II. GASTEROPODA. 
Gasteropoda, Cuvier. 
Vermes Testacea Univalvia, Linné. 
Mollusca, Ordo Gasteropoda, Lamarck. 
Cephalophora, De Blainville. 
Ordinum Synopsis. 
* Sexus hermaphroditus. 
I. GyMNOBRANCHIA. Branchie nullo modo tecte, dorsales. 
Testa nulla. 
Il. Srecoprancuia. Branchie dextre, laterales aut dor- 
sales, sub pallii processu tectze. J'es¢a interior aut exterior. 
Tif. Saccoprancuta. Branchie saccum interné tegentes et 
non elevate. Testa interior, aut exterior vel nulla ; nun- 
quam operculata. 
** Sevus distinctus. 
IV. Puytioprancutia. Branchie & foliis plurimis paral- 
lelis efformatee. Testa exterior, spiralis, in plurimis oper- 
culata. 
VY. Anrroprancuia. Branchie saccum cavum interné te- 
gentes, non elevate. Testa exterior, spiralis, operculata. 
*EX Sexus androgynus. 
Vi. Asprpoprancuia. Branchie é foliis plurimis efformate, 
sub testa posite. Testa exterior, non operculata. 
Vif. CycLtoprancutia. Branchie & foliis efformatee, inter 
pedis basin et pallium posite. Testa seepius exterior, 
seepe multipartita, nunquam operculata. 
