MOLLUSCA OF THE ' CHALLENGER ' EXPEDITION. 423 



leaving the body it sweeps at once to the left, leaving a very nar- 

 row shelf between the body-whorl and the sinus, which is rounded, 

 rather shallow and open, but large, from the very considerable 

 forward sweep of the pinion-like edge of the lip as it approaches 

 the canal, from which it retreats toward the point of the shell. 

 Inner Up is a thin-glazed, narrow, slightly depressed area ; it is 

 very slightly hollowed at the base of the longish, finely conical 

 pillar ; the point of the pillar is cut off with a long-drawn obli- 

 quity, and has a fine, slightly twisted edge. H. 0'3. B. 0*1. 

 Penultimate whorl, height 0*05. Mouth, height 013, breadth 

 0-06. 



This species resembles P. syngenes, W., in general character 

 of its whorls and style of its sculpture ; but its longitudinal 

 ribs are a marked feature of difference. It is, besides, a much 

 narrower shell, with a larger apex, a much smaller body, and a 

 less contracted base with a much shorter pillar. Its weaker 

 sculpture and slimmer form distinguish it at once from P. 

 lophoessa, W. In shape it is very like P. ischna, W., and P. 

 bolbodes ; but these are in sculpture and in texture unlike it and 

 one another. 



25. Pleurotoma (Drillia) ph^eacra, n. sp. ((f>a(aKpos, dun- 

 tipped.) 



St. 122. Sept. 10, 1873. Lat. 9° 5' S., long. 34° 50' W. Per- 

 nambuco. 350 fms. Mud. 



Shell. — High, conical, with a blunt, dun apex, a contracted 

 base, a longish pillar; angulated, tubercled, thin, polished, glassy. 

 Sculpture. Longitudinals — there is no other longitudinal sculp- 

 ture than the fine scratch-like lines of growth. Spirals — toward 

 the bottom of each whorl is a row of about twelve round, blunt- 

 tipped, rather prominent tubercles, which form an angulated keel 

 where otherwise there is no carination ; there is also a slight blunt 

 keel round the base : the surface is covered with very obsolete, 

 rounded, flat threads. Colour polished glassy white, with a hya- 

 line dun apex. Spire high, rather narrow, conical ; its profile-lines 

 little interrupted by the carinal tubercles. Apex : there are 

 about two glossy, dun-coloured, globose, embryonic whorls ; the 

 extreme tip is rounded and slightly bent down on one side. 

 Whorls 6, short, and of slow growth, with a longish, drooping, 

 somewhat concave shoulder, angulated below the middle by the 

 row of tubercles, and slightly contracted into the inferior suture. 



