HYDATINA. 389 



defined white girdles; one at vertex, one occupying the baso-umbil- 

 ical tract, the others of equal width, equally spaced. Surface 

 smooth ; aperture ovate, narrowed and curved above, broadly 

 rounded below. Columella concave, reflexed. 



Alt 35, diam. 30 mill. 



Alt. 36, diam. 26 mill. 



Nagasaki, Japan (Birileff) ; China ( Adams) ; Philippines (Jay); 

 Port Stephens, N. S. Wales, Australia (Braz.). 



Bulla albocincta Van der HOEVEN, Tydschrift voor natuurlyke 

 Geschiedenis en Physiologic, Leyden, vi, 1839, p. 246, pi. 10. AD., 

 Thes. Conch., ii, p. 566, t. 120, f. 17, IS.Hydatwa albocincta SOWB., 

 Conch. Icon., pi. 2, f. 3. ANGAS, P. Z. S. 1877, p. 189. LISCHKE, 

 Jap. Meeres-Conch., ii, p. 105. Bulla ferruginosa PERRY, Con- 

 chology, pi. 40, f. 2, 1811. Not B. ferruginosa Gmel. 



As in the other species of Hydatina, the color-pattern is charac- 

 teristic, consisting of white alternating with brown-streaked zones. 

 The name given by Perry is preoccupied, and his figure is hardly 

 recognizable. 



H. INFLATA Dunker. PL 44, figs. 11, 12, 13. 



Shell large, inflated and globose, umbilicated, rather thin, semi- 

 pellucid; ashy and pale brown, very densely streaked longitudinally, 

 and marked in the lower part by one white belt split by a brown 

 line ; a wide white band adjacent to the umbilicus ; spire deeply 

 immersed, milk-white within. Alt. and diam. 44 mill. (Dkr.). 



Inland Sea of Japan, at Wakayama. 



Hydatina inftata DKR., Malak. Bl. xxiv, p. 69, 1877 ; Index 

 Moll. Mar. Jap., p. 162, pi. 2, f. 14-16. 



Evidently allied to S. albocincta, but broader, with larger umbil- 

 icus, and lacking the broad white zones, which are here represented 

 by one narrow girdle, and apical and umbilical patches. 



Subgenus APLUSTRUM Schum., 1817. 



Aplustrum SCHUM., Essai, pp. 63, 208, type A. fasciatum Schum. 

 =B. amplustre Linn. Aplustra SWAINS, Malacol. p. 248. Bullina 

 (in part) FERUSSAC (see ant., p. 175). 



Shell obovate,thin, vividly banded, covered with a thick corneous 

 cuticle. Columella truncated at base, the aperture notched there. 

 Type H. amplustre. 

 26 



