100 



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



Fig. 201. 



Triincatella su1>cyliiidrica, Gray. — Shell scarcely rimate, 

 cylindrical, furnished with regular, crowded ribs, less 

 prominent or obsolete at the suture, shining, pellucid, 

 yellowish horn-color or hyaline ; remaining whirls four, 

 rather convex, flattened in the middle, regularly increas- 

 ing, the last not ridged on the base ; aperture vertical, 

 ample, angularly oval, sub-efl"use at base ; peristome 

 lightly thickened, its external margin sub-produced, the 

 columellar portion briefly reflected, appressed and above 

 thickened. Length 5, breadth 2 mill. 



Helix subcylindrica, Pulteney, Cat. Dorsetsh. 49. — 



Montagu, Test. Br. II, 393. 

 Triincatella subcylindrica, Gray in Turton's Man. 22, f. 

 6. — Shcttleworth, Diagn. 7, 154. — Pfeiffer, Mon. 

 Auric. Viv. 187 ; Mon. Phan. Viv. II, 7 ; Br. Mus. 

 Cat. 136.— W. G. BiNNEY, T. M. IV, 186, pi. Ixxv, 

 f. 5, 6, 8.— Orbigny, Moll. Cub. II, 5 (excl. T. truncatula'). 

 Truncatelln truncatula, LowE in Zool. Proc. 1845, 217?; in Zool. Journ. 



V, p. 299, tab. xiii, f. 13-18? 

 Truncatella caribspcnsis, Pfeiffer in Zeitsch. f. Mai. 1846, 182, ex parte. 

 — KiJSTER in Chemn. ed. 2, Auric, pi. ii, f. 1-4. 



A West Indian species found on the Florida Keys. 



Trimcatella 



iuhci/lindrica, 



enlarged. 



Fig. 202. 



Truncatella californica, Pfr. — Shell not rimate, cylindrical, 

 truncated at tip, thin and translucent with light strise, shin- 

 ing, amber-colored ; spire in the perfect state of the shell 

 composed of about ten whirls, of which four only are not 

 deciduous ; these are convex, increasing in size rather rap- 

 idly ; aperture oval, vertical, rounded above ; peristome 

 simple and continuous, slightly expanded, its pillar margin 

 scarcely attached to the shell. Length 4§, diam. If mill. 



Truncatella californica, Pfeiffer, Proc. Zool. Soc. London, 

 May, 1857, 111 ; Mon. Pneum. Viv. II, 7.— W. G. Bin- 

 NEY, T. M. U. S. IV, 28, pi. Ixxix, f. 20, 22. 

 Truncatella gracilenta, Godld, Proc. Phila. Ac. Nat. Sc. X, 1858, errata. 



San Diego, California. 



Family KERITID^. 



Jaws two, above and below, with denticulated margins. 

 Lingual dentition very similar to that of the Trochidse ; the 

 central teetli few, the lateral hooks, or uncinai, very numer- 



