362 CANCELLARIADiE. 



The shape of this curious shell, which, although of not 

 very solid texture, may be termed strong as compared 

 with its congeners, is of a somewhat turreted oval or 

 oboval figure, acuminated at both extremities, more 

 abruptly so in front, more gradually and slenderly so 

 behind. Its surface, which is of an uniform white, or very 

 pale fulvous orange, is veiled externally by a membra- 

 naceous epidermis of a squalid yellow hue ; this becomes 

 lamellar at regular short intervals, and is there produced 

 into lanceolate bristles upon the raised spiral sculpture. 

 Two principal narrow, but much projecting, rounded cord- 

 like ribs, one medial, the other subbasal, with oftentimes a 

 rather smaller intervening one, revolve around the volu- 

 tions of the spire, and are succeeded upon the body- whorl 

 by about five or six moderately distant additional ones 

 (each occasionally with a very fine intermediate parallel 

 costella) ; moreover the entire surface is longitudinally 

 corrugated by most densely disposed delicate raised thread- 

 like lines, which are peculiarly oblique beneath the suture, 

 where two or three very depressed narrow costellaj are 

 visible above the principal costse. The body, which tapers 

 somewhat retusely at the base to a very sharp point, is 

 very slightly, if at all, longer than the spire, which consists 

 of five moderately high rather quickly increasing volutions, 

 that are divided by a peculiarly broad and profoundly 

 excavated moderately slanting suture, and are obliquely 

 subplanulate above, and nearly perpendicularly erect below. 

 The apex, which is frequently a little arched, is small, 

 but not very acute ; it is somewhat obliquely coiled, so as 

 to remind one a little of the nucleus of Odostomia. About 

 one half of the ventral length is filled by the rather large 

 aperture, which is usually white, more rarely and only 

 in such as are tinged with colour externally, of an orange 



