98 



LAND AND FRESH- WATER SHELLS OF N. A. [PART III. 



arc also truncated in the adult, the remaining ones are usually 

 gradually increasing in size, and covered with more or less 

 strongly developed ribs ; the peristome is simple or double, some- 

 times reflected ; the base is generally furnished with a prominent 

 carina or ridge, formed by the peristome. Aperture rounded. 

 Dr. Gray describes Truncatella with distinct white jaws. 



The teeth of T. caribaeensis, by Tro- 

 schel: Central rather narrow, conical, 

 apex recurved ; first lateral very broad, 

 apex recurved, denticulate ; second 

 lateral narrower, denticulated ; outer 



Lingual dentition of Truncatella 



cari6aen««.-[TKoscHEL.] lateral uarrow, simple. 



Fig. 197. 



Fig. 198. 



Truncatella caril>aeeiisis, Sowb, — Shell subrimate, subcjlin- 

 drical, rather solid, iu its truncated state but slightly 

 decreasing in size towards the apex, reddish, or dark 

 amber-colored, with delicate ribs, which are but little 

 curved, and often hardly perceptible on the middle of the 

 whirls ; suture slight ; whirls not truncated, three or four, 

 distinctly increasing in size, equally convex, the last 

 often smooth, slightly carinated on its base ; aperture 

 subvertical, ovally elliptic, angular above ; peristome 

 continuous, straight, thickened at its connection with 

 the penultimate whirl. Length 7-8, diameter 3 milli- 

 metres ; length of aperture 2 J millimetres. 



Truncatella caribaeensis, Sowerby MSS. — Reeve, Conch. 



Syst. 11, t. clxxxii, f. 7. — Pfeiffer in Zeitsch. f. 



Mai. 1846, 182 ; Mon. Auric. Viv. II, 185 ; Mon. 



Phan. Viv. II, 7; Brit. Mus. Cat. 134.— W. G. 



Bisnet, T. M. IV, 185, pi. Ixxv, f. 2, 4.— Chemnitz, 



ed. 2 ; Auric, p. 9, pi. i, f. 35, 36 ; pi. ii, f. 22 ; not pi. ii, f. 2-4. 



Truncatella gouldii, Adams, ined. 



Truncatella succinea, Adams, Proc. Bost. Soc. 1845, 12. 



Florida Keys, Mexico, Alabama ; also Cuba and Jamaica. 



