On the Clausilice of America. 225 



The Genus does not occur in North America; two, C. peruana 

 and C. episto7nium, inhabit South America, and one, C. tridens, 

 is found in the Island of Porto Eico. The Porto Rico species 

 is described and figured by Chemnitz in his work, published in 

 1786, but Fdrussac first gave the correct habitat in 1821, on the 

 authority of Maugd. C. peruana was described by Troschel, in 

 April, 1847, as the only known American species, excepting 

 C. tridens, and in the same year Kiister described and figured 

 C. epistomima. 



The Genus Clausilia was instituted by Draparnaud in 1805, 

 but the claiisium had been described by 0. F. Miiller in his 

 Hist. Vermium, &c., 1773, and afterwards by Daubenton in the 

 Mem. de I'Acad. des Sciences. See Mr. Gray's paper in the 

 Zool. Journ. I. 212. We detected the clausium in six of our 

 specimens of the C. epislomium, and in several of the C. tridens. 



1. Clausilia tridens. 



Synonymy. 

 Clausilia tridens (Turbo) Cliem. IX. P. 1. p. 115, t. 112. 



f. 957. 1786. 



Turbo labiatus Dillw. Descr. Cat. II. p. 875. No. 146. 



in parte. (1.) - - - - 1817. 

 Clausilia tridens Sohweigg. Naturg. p. 741. teste Pfr. in 



Mon. Ilel. Viv. - - - . 1820. 

 Helix hicanaliculata (Cochlodina) Fer. Prod. p. 62. No. 523. 1821. 

 Clausilia costulata Lam. An. sans Vert. VI. pt. 2. p. 113. 



No. 4. 1822. 



Bowd. EL Conch, pt. 1. 1. 8. f. 28. ?? (2.) 1822. 

 Clausilia lahiata Sowb. Gen. fasc. 30 Clausilia, f. 3. (3.) 1824. 



Turbo costulatus Wood Suppl. t. 6. f. 36. 1828. 



Clausilia tridens Beck. Ind. p. 00. No. 1. 1837. 



costulata Desh in Lam. An. sans Vert. VIII. p. 198. 



No. 4. 1838. 



Pfr. Synib. I. p. 47. teste Pfr. in Mon. 



Ilel. Viv. 1841. 



Rossm. XL p. 8. No. 718. t. 52. f. 718. 1842. 



lablala Rv. Conch. Syst. IL p. 77. t. 171. f. 3. (4.) 1842. 



co6tulata Catlow Conch. Norn. p. 146. No. 40. (o.) 1846 



