DYTiilNELLA. 



69 



Paludina nicldlniana, Lea, Tr. Am. Phil. Soc. VI, 92, pi. xxiii, f. 109 



(1839) ; Obs. II, 92. 

 Amnicola nickliniana, Haldeman, Mon., p. 21, pi. i, f. 12 (1844?). 



Mr. Lea's figure (Fig. 133) not being as correct a representation 

 as desirable of the species, I add another (Fig. 134), copied from 

 Haldeman. 



The lingual dentition is figured on page 131. 



Bytllinella tenilipes, Coupek. — Animal " with the head pro- 

 boscidiform, sub-bifid, sub-cyliudrical ; foot strap-shaped, anterior portion 

 extending laterally, and emarginate before ; tentacles setaceous ; ejes at the 

 external base of the tentacles ; color, except the head and eyes, mottled white. 



Shell " small, one and a half lines long, subumbilicated, oblong-ovate, 

 turreted, thin, smooth, lines of growth very slightly marked ; 

 color light brown ; volutions five, suture slightly impressed ; 

 aperture ovate, oblong, angulated above, rounded at base ; la- 

 brum simple, sharp. 



" Found in the rice-field ditches at Hopeton, Georgia ; move- 

 ment active, made by the joint action of the head and foot, 

 the head advancing before the foot ; floats on the surface of the 

 water in an inverted position." {t'ouper in Haldeman.) 



Amnicola tenuipps, Coupee, in Haldemax's Mon. 23, pi. i, f. 14-15 (1844 ?) ; 

 No. 7, p. 4 of wrapper (1844). 



Fig. 135. 



Bytlmulla 

 tenuipes. 



Fig. 136. 



Bytllinella Ijiiiiieyi, Tryon. — Shell minute, elongated, con- 

 sisting of 4 to .5 very convex whirls ; apex somewhat obtuse ; aperture 

 ovate or nearly suborbicular, both lips rounded ; umbilicus 

 very small. Color light horn. Length 3, diam. 1.(3 ; length 

 of aperture 1.25, breadth 1 mill. 



Bolinas, California. Rev. J. Powell. My cabinet and cabi- 

 net of Mr. Powell. Some specimens of this very small and 

 exceedingly fragile species were sent to me ; they exhibit, how- 

 ever, all the stages of growth from the very young to adult 

 form. None of them retained the operculum. It is much 

 smaller than any other species of Pomntiopsis, and is not likely 

 to be confounded with any of them. It approaches nearest in ^\ 



form to two European species of Bj/thinia, B. anttn and D. ^^\ 

 viridis ; the former, however, has a more lengthened, acute ^-^ 



sjiire, and the latter is a more robust and ventricose shell. sMiinella 

 (Trtjon.) ^ binneyi. 



Pomati- 



nrpsis 

 biiintn/i. 



Fig. 137. 



