226 



ZONITIDJ. 



Helix tiu-biniformis, Bs. J. A. S. B. vii, 1838, p. 218 (no description): 

 nee Pfr. 1839, 



Shell subperforate, subtrochiforiu, thin, not polisbed above, 

 faintly striated obliquely, with longitudinal (spiral) raised lines 

 often obsolete on the lower whorls, and finer ribbing intercalated 

 between them, translucent, greyish horny; spire conical, suture 



B 



»-«' M 





3^1M^^ 



[Fig. 78. — Sitala wfula. 



A. Animal from life (after Stoliczka). 



B. Mantle-zone, showing shell- and dorsal lobes (after S'toliczka). Enlarged. 



C. Jaw. X 30. 



D. Teeth of radula. x 475. 



E. Generative organs (after Stoliczha). Enlarged. 



Sitala aitecjla. 



F. Generative organs (after Stoliczka). 



Sttala vulcania. 



G. Part of the generative organs. X 3"4.] 



