50 BYTHINELLA. 
8. BYTHINELLA BINNEYI, Tryon. 
Plate 16, fig. 8. 
Shell minute, elongated, whorls four to five, 
apex somewhat obtuse; aperture ovate or 
nearly suborbicular, both margins rounded ; 
umbilicus very small. Color light horn, trans- 
lucent. 
Alt. 3, diam. 1-6 mill. 
Bolinas, California. 
A narrow, smaller, more elongate and more 
fragile form than the preceding. 
-_- 
9. BYTHINELLA SEEMANI, Frauenfeld. 
Plate 16, fig. 9. 
Shell elongate, very narrow, whorls five and 
a half, convex; aperture very small, oval ; 
umbilicus narrow. Greyish-green, translucent. 
Alt. 4, diam. 1:8 mill. 
Durango, N. W. Mexico. 
Narrower than the preceding species. 
(31) 
