82 AmticuLnxE:. 



niellar margin dilated, slightly spreading. Length 2|, breadth 

 li mill. 



Plecotrema Cubensis, Pfr. in Malak. Bl. 1854, p. 158 ; Syn. 

 Auric, n. 108 ; Mm. Auric, p. 107. 



H. and A. Adams, Gen. rec. Moll. ii. p. 241. 



Hab. Me of Cuba (Gundlach). 



7. CASSIDULA, Ferussac. 



Shell rimate, cassidifomi, solid; spire short, conoidal; last 

 whorl large, attenuated at base, provided usually with a keel 

 surrounding the umbilical region ; aperture narrow, sinuate ; 

 body of the penultimate whorl bearing various teeth ; columel- 

 lar plait strong ; right margin of the peristome thickened, with 

 a longitudinal internal callus, which is sinuated above. 



Cassidida, Ferussac, 1821, Prodr. p. 105. 



Latreille, Fam. Nat. p. 181. 



Rang, Man. p. 173. 



Gray in Proc. Zool. Soc. 1847, p. 175. 



H. and A. Adams in Proc. Zool. Soc. 1854, p. 31 ; Gen. rec. 

 Moll. ii. p. 238. 



Pfr. in Malak. Bl. 1854, p. 150; Mon. Auric, p. 108. 

 Cassidulus, Berthold, 1827, in Latr. Fam. p. 176. 



Beck, Ind, p. 105. 

 Rhodostoma, Swains., 1840, Malak. p. 344. 



Herrrnannsen, Ind. Gen. Mai. ii. p. 392. 

 Sidula, Gray, 1840, in Tart. Man. p. 21 ; Syn. Brit, Mus. 1842, 



pp. 70, 91. 

 Voluta, sp., Linn., Cliemn., Gmel. 

 Ellobium, sp., Bolt. 

 Limax, sp., Marty n. 

 Bulimus, sp., Bruff. 

 Helix, sp., Gmel. 

 Auricula, sp., Lamarck et Auctt. 



This genus, which is better characterized by its peculiar 

 habit than by an exact description, has been proposed by Fe- 

 russac as a section or subgenus of Auricula, and adopted by 

 the above-quoted writers. The typical species are provided 

 with a more or less distinct basal keel, and by this character we 

 may divide the genus into two sections : — 



A. Aberrant, with the basal keel indistinct . . . § 1. No. 1- 2 



B. Typical Cassidulse § 2. - 3-10 



C. Little-known species § 3. - 17-19 



