108 CASSIDULA, 
VII.  Cassidula Férussac, 
Testa rimata, cassidiformis, solida; spira brevis, conoidea ; 
anfractus ultimus magnus, basi attenuatus, plerumque carina 
periomphalum cingente munitus: apertura angusta, sinuosa; 
paries aperturalis varie dentatus; plica columellaris valida; 
peristomatis margo dexter incrassatus, intus callo longitudinali, 
superne sinuoso, munitus. 
Cassidula Férussac 1821 Prodr. p. 105. 
-— Latreille 1825 Fam. nat. p. 181. 
— liang 1829 Manuel p. 173. 
- Gray 1847 in Proc. Zool. Soc. XV. p. 175. 
— H. et I4. dams 1854 in Proc. Zool. Soc. XXIL. p. 31. 
-— Pfr. 1854 in Malak. Bl l|. p. 150. 
— H. et 4. )ddams 1855 Gen. rec. Moll. Il. p. 238. (Conf. 
supra p. 6.) - 
Cass du'us Berth. 1827 in Latr. Fam. p. 176. 
— Beck 1837 Ind. p. 105. 
lihodostoma Smains. 1840 Malac. p. 344. *) 
— FHerrmannsen 1848 Ind. gen. Malac, ll. p. 392. 
Sidula Gray 1840 in. Turt. Man, p. 21 (nomen) et 1842 Syn. Brit. Mus. 
prn: 9152) 
Volutae sp. Linn , Chemn , Gmel. 
Ellobi sp. Bolt. 
Limacis sp. Martyn. 
Bul.mi sp. Brug. 
Helicis sp. Gm. 
Auriculae sp. Lam. et Auct 
Genus habitu peculiari potius quam characteribus exacte 
circumscriptis cognoscendum, primum a Cl. Férussac tam- 
quam sectio vel subgenus Auriculae propositum, a pluribus 
auctoribus exinde adoptatum. Species typicae omnes carina 
periomphalum cingente magis minusve distincta munitae sunt; 
nonnullae autem existunt, hoc charactere carentes et generi 
Plecotremae quodammodo affines, quare distinguamus: 
A. Abnormes, carina basali indistincta $. l. Nr. 1—2. 
B. Carina basali distincta. . . . $2. — 3-106. 
C. Species minus cognitae . . . . $3. — 17—19. 

*) General form of Melampus and Tornatella : but the aperture is 
not striated, and the inner margin of the lip is broad, considerably thicke- 
ned, and distinctly notched towards the top. (Swains. l. c ) 
**) The Sidulae have a sharp internal ridge to the outerlip. (Gray l. c.) 
