CYLICHNA. 221 



front, hy tlic curvature of the inner lip ; occasionally the lip is a 

 little waved inwards at the middle, narrowing the aperture ; at the 

 region of tlie umbilicus is a flattened, white space, thickened by en- 

 amel, gradually disappearing within the aperture ; the whole inner 

 margin is sometimes slightly coated with enamel. Length, one 

 fourth of an inch ; breadth, one tenth of an inch. 



Found plentifully in the maws of fishes taken in Massachusetts 

 Bay. Connecticut (^Linsleij^ ; Grand Manan {Stunpson) ; Maine 

 {31i<y-hcls) ; Greenland QMorch) ; Fishing Banks {Wiliis). 



This shell is analogous to the Bidla cylhidracea of Pennant (Brit. 

 Zool. pi. 70, fig. 85). But that is a much longer shell, and de- 

 cidedly uml)ilicated in the region of the spire. Brown figures a 

 shell under the name of Volvaria alba (Conch, of Great Brit., &c., 

 pi. 38, figs. 43, 44), which bears a striking resemblance to this 

 shell. [It is now considered identical. 



Cylichna oryza. 



Fig. 93. 



Shell minute, white, glossy, sub-oval, last whorl enveloping all the others, and 

 marked with a few revolving lines ; summit depressed, imperforate. 



Bulla oryza, Totten, SilHman's Journ. Old Scries, xxviii. 350, fig. 5 (1835). — Gould, 



Inv. 16S, fig. 93. -De Kay, N. Y. Moll. 18, pi. 31, fig. 327. 

 Cylichna oryza, Stimpson, Check Lists, 4 (1860). 



Shell not very small, not very thin, translucent, white, regularly 

 diminishing from the middle towards each end, the tip being de- 

 pressed into a shallow pit, and the front being rather pointed ; 

 last whorl enclosing all the others ; surface marked with mi- 

 nute lines of growth, a few revolving lines on the anterior 

 portion, and a few more ol)SCure ones near the shoulder, none 

 of them perceptible without a magnifier. Aperture as long 

 as the shell, narrow behind, and widening forwards ; outer lip sim- 

 ple and sharp, commencing beyond the axis of the shell, and rising 

 a little, then turns, and ])asses forwards by a regular curve ; the 

 left margin is thickened and forms a smooth, glossy pillar, which is 

 twisted so as to form an oblique fold ; at the base it terminates 

 abruptly, so as almost to form an obtuse tooth ; a thick callus, com- 

 mencing at the junction of the outer lip, runs round within the 

 wdiorl, giving strength to the region of the spire. There is no um- 

 bilical opening either at the ti]) or l>ase. Length, three twentieths 

 of an inch ; breadth, one tenth of an inch. 



