22 



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



Fig. 14. 



aperture subcircular, edentulate ; peristome 

 expanded, continuous. 



No jaw. 



Teeth of the lingual ribbon joined at the 

 base two by two, and placed in chevron- 

 like rows, inclining obliquely to the centre 

 of the ribbon. 



LiDifual' dentition of 

 Cylindrtlla scava. 



ScBGENPs GONGYLOSTOMA, Albers. 



Shell cylindrically-fusiform or conic-turreted, apex attenuated, 

 costellately-striate ; whirls 9-20, the last more or less protracted, 

 terete, sometimes obsoletely angulated ; aperture circular, peri- 

 stome expanded in every part. 



Animal small and short compared with the shell, in general 

 like that of Helix ; eye-peduncles of medium length, the tentacles 

 quite short. Motions sluggish ; the shell drags horizontally, 

 nearly in the line of motion. , 



Cylindrella poeyana, D'Orbigny. — Shell very long, thin, horn- 

 colored or whitish, longitudinally strongly striated ; 

 Fig. 15. spire very long, inflated, acuminate behind, trun- 



cated ; whirls eleven, rather convex, the last cari- 

 nated before ; aperture round ; peristome acute and 

 continuous, in contact with the preceding whirl. 

 Axis simple. Length 15, breadth 4 mill. 



Pupa poeyana, D'Orbigny, Moll. Cuba, I, 185, pi. 



xii, f. 24-26. 

 Cylindrella poeyana, Pfeiffer, Mon. Hel. Viv. 11, 

 Cylindrella poeyana. 380. — Chemnitz, ed. 2, 20, pi. iii, f. 29-31. — 



W. G. BiNXEY, T. M. IV, 149. 

 Cylindrella lactaria, Gould in T. M. pi. Ixix, f. 2, not in text. 



' Not being able to obtain the animal of any North American species, I 

 Lave figured the lingual membrane of C. sca;va, Gundl., from Cuba, kindly 

 furnished me by Mr. Bland. There are no less than 130 chevron-like 

 rows of 53 teeth each (2G — 1 — 26) ; the central very small, obtusely 

 pointed, laterals uncinated, thorn-like, joined two by two ; the upper edge 

 of the plates are fringed. 



