KEPORT ON THE GASTEROPODA. 541 



4. Bittium enode, Watson (PI. XXXIX. fig. 3). 



Cerithium {Bittium) enode, Watson, Prelim. Report, pt. 5, Journ. Linn. Soc. Lond., voL xv. p. 115, 



sp. 16. 



Station 120. September 9, 1873. Lat. 8° 37' S., long. 34° 28' W. Off Pernambuco. 

 675 fathoms. Eed mud. 



Shell. — Small, narrow, conical, finely ribbed, but not reticulated nor tubercled, thin, 

 white, apex blunt and mamillated, outlines straight, square on the base. 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 interstices five to six times as much ; toward 

 the apex they become more crowded. In the interstices a feebler riblet is occasionally 

 intercalated. They die out on the base with a strong, posteriorly convex curve. Spirals — 

 near but not just at the suture the top of each whorl projects in a sharp minute carina, 

 defined by a spiral thread, which forms a small knot in crossing each riblet ; about one- 

 third down the whorl a very fine sharp thread runs round the shell, rising over, but scarcely 

 forming knots on the riblets. Two-thirds down another very faint thread appears. The 

 margin of the base is defined by a sharp, minute, knotted, carinal thread, the edge of 

 which may be faintly traced at the bottom of each whorl, just above the suture, all the way 

 up the spire. The base is plain but for a very faint submarginal thread. The apex is smooth 

 and glossy, with nothing but microscopic evanescent superficial spirals. Over the whole 

 surface of the shell there is a microscopic reticulation of faint, pretty equal, longitudinal 

 and spiral scratches. Colour ivory white. Spire high, narrow, with perfectly straight 

 conical outlines. Apex truncate, and then finished with a slightly depressed mamillate, 

 glossy, pure white tip, consisting of a whorl and a half, which is straight on the top and 

 not oblique. Whorls 9, straight or just faintly concave on the side, slightly scalar as they 

 rise out of one another. The base is not in the least contracted, and is barely convex. 

 Suture only recognisable from the slight shoulder of the whorl below it. Mouth small, 

 angularly oval, with a blunt and laterally directed point above, and an oblique canal in 

 front, which, relatively to the size of the mouth itself, is very large. Outer lip very 

 straight, being neither incurved nor patulous, except round the edge of the canal, where it 

 is slightly so. Pillar very short and conical, with an abrupt little broad parallel-sided 

 style, with a very oblique, fine, rounded edge, and ending in a fine point on the left. 

 Inner lip a fine glaze on the body and edge of the pillar. H. 0*19 in. B. 0"06. Penulti- 

 mate whorl, height 0'028. Mouth, height 0'039, breadth 0-028. 



This is a peculiarly beautiful shell, and, like Bittium mamillanum, Wats., from the same locality, 

 departs widely in sculpture from the coarse type common to the genus. From that species it differs 

 markedly in its being much stumpier in form and in the carina being placed at the top and not at 

 the bottom of the whorls. From Bittium amblyterum, Wats., another deep-sea form, which it also 

 resembles slightly, it differs in being stumpier and in having a much blunter and shorter apex. 



