MOLLTTSCA OF THE 'CHALLENGER' EXPEDITION. 115 



Shell. — Small, narrow, conical, blunt, with convex outlines, 

 contracted both toward the apex and the point of the base, reti- 

 culated, tubercled, solid, translucent, glossy, white. Sculpture. 

 Longitudinals — there are on the last whorl about 25 rows of 

 small, roundea, adjacent tubercles ; they are parted by mere 

 lines, and run pretty straight, but with a slight sinistral turn 

 down the spire. On the upper part of the spire the rows are 

 straight, but in the penultimate whorl, where the shell begins to 

 contract toward the base, the rows have a slight concave and 

 dextral curve. Spirals — on each whorl there are three equal 

 spiral threads, which form the tubercles as they cross the longi- 

 tudinal rows ; they are parted by two narrow and shallow fur- 

 rows ; there is a strong deep sutural furrow. Besides these 

 there are quite inconspicuous microscopic longitudinal and spiral 

 lines on the surface. The very narrow base is encircled by a 

 strong rounded prominent thread, within which a deep furrow 

 surrounds the pillar. Colour translucent white. Spire high 

 and narrow, with convex outlines. Apex extremely abruptly 

 truncate, rounded. The smooth embryonic shell consists of 

 one and a half whorls, and the tip of it scarcely rises into sight. 

 Whorls 9, contracted upwards, flat on the sides. The base is 

 extremely contracted ; and as the contraction begins in the 

 penultimate whorl, the form of the shell resembles the pupa of 

 an insect. Suture only defined by the deep furrow in which it 

 lies. Mouth oval, with a very small channel in front. Outer lip 

 broken. Pillar very short, strong, but not broad; the point is 

 in the only specimen slightly broken. L. 0*1. B. O037. Pen- 

 ultimate whorl 002. 



In general form, but in that alone, this is very like some of 

 the ill-thriven looking forms of Cerithiopsis minima, Brusina, but 

 is obviously very different. 



16. Ceetthium (Bittium) enode, n. sp. 



St. 120. Sept. 9, 1873. Lat. 8° 37' S., long. 34° 18' W. Off 

 Pernambuco. 675 fms. Mud. 



Shell. — Small, narrow, conical, apex blunt and mammillated, out- 

 lines straight, square on the base, finely ribbed, but not reticulated 

 nor tubercled, thin, white. Sculpture. Longitudinals — there are 

 on each whorl about 26 small, narrow, sharp, curved distant ribs, 

 which run continuously from whorl to whorl, and very straight 

 down the spire. The ribs are about O'OOl in. wide, and the in- 

 terstices five to six times as much ; toward the apex they become 



