132 MITRELLA. 



to its length ; the aperture is shorter and differently shaped, the 

 pillar being straighter and the denticnlations of the outer lip 

 stronger. The animals differ; the tentacles of G. spirantha are 

 delicate and hair-like, while in C. lunata they are rather thick 

 for the size of the animal. 



I copy Ravenel's description above in full. It is evidently a 

 critical species, and Stimpson considered it a doubtful one. It 

 has never been figured, and our specimens (not received from 

 Ravenel, although from the vicinity of his locality) are entirely 

 too close to C. lunata. 



C. NIVEA, Ravenel. 



Shell small, delicate, elongated-conic, white, immaculate, 

 smooth, polished, prettily striated on the outer part of the canal, 

 body-whorl longer than the spire, suture distinct, with a white 

 revolving line a little below it on the whorls ; pillar covered with 

 callus, much hollowed, suddenly becoming straight to form the 

 canal ; callus ending in a distinct edge ; outer lip a little thick- 

 ened, sparsely denticulated within, the posterior tooth being 

 decidedly the most prominent. 



Allied to rosacea, Gould, and lunata, Say. A single specimen 

 taken from the stomach of a fish. 



Off Charleston Bar, S. C. 



The above is a copy of the original description. I know 

 nothing of the species which is untigured. The specific name is 

 preoccupied by Sowerby. 



C. FENESTRATA, C. B. Adams. 



Shell much elongated, ovate conic, subangular on the middle 

 of the last whorl ; opaque white around the aperture, with, at the 

 summit of the whorls, a spiral opaque white band, which is inter- 

 rupted by the angles of an approximate series of brown spots, 

 which have the form of the summits of Gothic windows, and in 

 which the deep brown of the summit fades in descending to the 

 middle of the whorls, where the shell is transparent ; with three 

 linear spiral series of alternating white and brown on the middle 

 and anterior part of the last whorl ; with spiral striae anteriorly, 

 otherwise smooth ; apex acute, spire with nearly rectilinear 

 outlines; whorls eight, nearly plane, with a slightly impressed 



