HYDATINID^E. 385 



V. CANDIDA Pease. PI. 42, figs. 29, 30 ; pi. 48, fig. 11. 



Shell cylindrical, membranaceous, truncate posteriorly, much 

 convolute, covered with a thin yellowish epidermis ; aperture small, 

 not one-half the length of the shell. Animal white, pellucid, neck 

 long ; head disk elongate, triangular, with a posterior fissure, Ham- 

 inea-shaped, deeply fissured laterally. Foot oblong, rather wide 

 anteriorly, rounded behind (Pse.). 



Polynesia. 



V. Candida PSE., Amer. Journ. Conch, iv, p. 73, 160, pi. 7, f. 6 ; 

 pi. 12, f. 24. 



Resembles Cylindrobulla beauii Fischer (P.). 

 V. CUMINGI A. Adams. PI. 48, fig. 7. 



Shell subovate, gibbose, horny, fragile, pellucid, slightly involute ; 

 spire concealed ; aperture posteriorly produced, narrow and linear, 

 anteriorly greatly dilated ; outer lip slightly sinuous, greatly in- 

 flected towards the body whorl, posteriorly produced ; inner lip ad- 

 hering, slightly reflexed (Ad.). 



Puerto St. Elena, W. Columbia ; sandy mud, 6 fathoms (Cuming). 



Sulla (Lobiger*) cumin gii A. Ad., Thes. Conch, ii, p. 599, pi. 121, 

 f. 58. Oxynoe cumingii MORCH, Journ. de Conch. 1863, p. 47. 

 Volvatella cumingi FISCHER, Man. de Conch, p. 560. 



Family HYDAT1NIDJE. 



Aplustridce FISCHER, Man. de Conch, p. 560. 



Shell globose or oval, thin, with exposed, nearly level spire of 

 several whorls and minute, uptilted, nearly immersed nucleus. 

 Last whorl very large, with conspicuously banded color-pattern. 

 Aperture very large, the outer lip but little retreating toward its 

 upper insertion, broadly rounded below, sometimes notched at base 

 of the columella. 



Animal voluminous, the foot large and flat ; head disk bearing 

 four or two tentacular processes in front, produced in two large 

 lobes partly covering the shell behind. Radula lacking central 

 teeth, the laterals numerous and all of the same form. Digestive 

 tract very long. 



The radula resembles that of Akeridce except in lacking central 

 teeth. 



The present family differs from Akeridce in the absence of the 

 deep posterior bay or sinus of the aperture of the shell, and its con- 



