Genera of Terrestrial MoUusca, etc. 199 



nata3, numerosoe ; centralis tridenticulata, clenticulo medio elonsata; mediae 

 bidenticulatse, denticulo intenio elon,2,ato, externo brcvi ; marginales lati- 

 ores ina^qualiter trideiUiculata;, denticulis versus marginem exteriorem 

 gradalim miiioribus, intenio antcra valdc producto. 



"Genus naturale, Vitriiice uullo modo afflne, sed Sncciwce proximum. 

 Lamina lingualis autem diversa videtur (Cf. Phil. Handb., p. 243) atque 

 etiam Maxilla {Cf. Terr. Moll. U. S., I, p. 213, pi. xiii, fig. 3)." 



Heynemann (Mai. Blatt., 1868, p. 110, taf. v, f. 10) has 

 description and figures of the teeth of Simpulopsis sidcidosa 

 Fer., mentioning- that the jaw was not observed. On the 

 accompanying phite we have given (PI. ix, figs. 7, 8) copies 

 of several of Heynemann's figures of the teeth, as many of 

 our readers may not have access to the originals, and in a 

 subsequent part of this paper we have described them. 



With respect to the jaw not having been examined by 

 him, Heynemann refers to that fact as rendering the correct 

 classification of the genus difficult, but remarks that the form 

 of the linsual teeth suirgests relationshiii to the Orthalicea* 

 rather than to the Succinea, as shown by a comparison of 

 the marginals with those of B. auris leporis and papyraceus. 



H. and A. Adams (Genera, II, 127) adopt in Sucdmnce 

 the following genera: — Simjyulopsis, Succinea, Amphibit- 

 lima, Helislga and Omalonyx, enumerating as species of the 

 latter, O. unguis, appendlculata and ilepressa. 



On reference to our subjoined notes on the so-called Suc- 

 cinea appendicidata from Guadeloupe, it Avill be observed 

 that the form of its teeth aijrees sfenerally with that ascribed 

 by Heynemann to Simpidopsis sidculosa, Avhile his sug- 

 gestions as to the affinities of the latter genus (the jaw 

 being unknown to him) arc supported by our discovery of 

 the character of the jaw in the Guadeloupe species. It 

 must not, however, be overlooked that while the animal of 

 Simpidojjsis is entirel}^ covered by the shell, that of the 

 S. appendicidata under consideration is limaciform, like 



* It mu!-t be remembered that we use the term Orthalicince in a much more reetricted 

 sense than the Orthalicece of Albers and von Martens. See our notes on Syttematic 

 Arrangement, Ann. N. Y. Lye, x, p. 168. 



