64 THE XAUTILUS. 



ovate, about one-third the length of tlie entire shell ; peristome con- 

 tinuous, its plane oblique to the axis of the shell, the base of the 

 lip being advanced. Color, corneous, often encrusted with a black 

 ferrugineous deposit. Alt. 2'4, diani. 1 mm. 



The types were collected by Henry Hemphill near Kentucky 

 Ferry, Snake River, Washington. The species is more nearly allied 

 to B. Aldrichi Call, then to oar other forms, but is far more slender 

 than any Bythinella yet made known to us from North America. 

 The plane of the peristome slants forward toward the base, as in 

 the species of Pleuroeera, but the lip is not sinuous. This pecu- 

 liarity alone will separate B. HemphUU from all other species. 

 Bythinella brevissima Pilsbry. 



Shell narrowly umbilicated, pupiform, composed of 4 or 41 very 

 convex, rounded whorls, the first two increasing rapidly in width, 

 the last two more equal in width. Aperture a little over one-third 

 the length of shell ; oval ; the columellar side a little more flattened 

 than the outer ; peristome simple, continuous, in contact with the 

 body-whorl at the upper part, but not modified or flattened by that 

 contact. Umbilicus rather large. Surface slightly wrinkled longi- 

 tudinally. Alt. 2-8, diam. 1-8 mill. 



This species was collected by John H. Campbell, Esq, in Haul- 

 over Canal, at the head of Indian River, Florida. It was asso- 

 ciated with Byth. requicOstata, Hydrobia Wetherbyi, Goniobasis pap- 

 ulosa, Planorbis scalaris, Physa pomilia and Vivipara Georgiana. 



The shell seems most nearly allied to B. obtiisa and Aldrichi; 

 having the same truncated appearance caused by the depressed form 

 of the earlier whorls, while the last two form a rather cylindrical 

 body. The whorls are more convex than in B. obtitsa and the 

 umbilicus far larger, it being scarcely obvious in B. obfusa. B. Ald- 

 richi is a smaller species, with different aperture. 



A NEW SPECIES OF NANINA. 



BY H. A. PILSKRY. 



Nanina Ruschenbergeri Pil?bry. 



Shell large, depressed, thick and solid, rudely striate, deeply 

 and perspectively umbilicated. 



