250 PYRAMIDELLIDTE. 



of it appears in their Reports." It is of a slender tur- 

 reted form, moderately tliiii, slightly translucent and glossy, 

 and of an uniform white. There are usually eight whorls, 

 which are not simply convex, hut swell out .subangulately 

 rather below the middle, for the upper portion is flattish 

 or retuse, and gently shelves outwards, whilst the lower 

 portion is either perpendicular or has an inclination in- 

 wards. They are of rather slow longitudinal increase, at 

 least half again as wide as long, taper to a moderately 

 fine point, and are divided by a well defined and not much 

 slanting suture. Two closely disposed costellar lines, 

 which become tuberculated on meeting the numerous 

 (yet not crowded) oblique and prominent longitudinal rib- 

 lets, that ti-averse the superior portion of each of the prin- 

 cipal turns, encircle the lower area of the volutions which 

 compose the spire ; one or two additional spiral carinre 

 are present on the body, where a prolongation of the lon- 

 gitudinal costellse produces a distinct clathration ; beneath 

 them the base, which is short and but little convex, is 

 smooth or almost so. The intervals between each kind of 

 sculpture are broader tlian the sculpture itself, except the 

 space between the lower suture and the anterior carina, 

 which, if anything, is narrower. 



The mouth, which is of a rhomboid oval shape, occu- 

 pies about a fifth of the entire length, and more than 

 one-half of the basal diameter : the throat merely exhibits 

 the indentations of tlie external sculpture. The outer lip 

 is acute, straightish above, and abruptly arcuated below, 

 so as to meet the pillar lip, which is straightish, peculiarly 

 thin and narrow, and rather erect than appressly reflected, 

 at nearly a right angle. Specimens are usually a fifth of 

 an inch long, with a breadth of about one-fourth at most 

 of that measurement. 



