140 THE VOYAGE OF H.M.S. CHALLENGER. 



suture up the spire. Colour Avhite. Spire high aud narrow, conical. Apex broken. 

 Whorls — 10 at least remain below the embryonic shell; they are well rounded, and of 

 very slow increase both in height and in breadth. Suture deeply impressed by the curve 

 of the whorls ; it is linear, and has both above and below it a miuute flat border. Mouth 

 broken, but apparently very round and oblique, a little angulated at the basal keel. 

 Inner lip inconsiderable, very thin on the body, slightly reverted on the pillar. H. - 42 in. 

 B. 0-1. Penultimate whorl, height 0-06. Mouth, height 0-07, breadth 0"07. 



This species has some resemblance to Scalaria varicosa (S. Wood.?), G. O. Sars, but is much 

 narrower, with smaller and more numerous whorls ; and the base is much squarer, and is not con- 

 tracted. It extremely resembles Ccrithiopsis costulata, Moll., but is a larger shell, and under a 

 superficial resemblance the whole sculpture, both longitudinal and spiral, is quite different. 



4. Scalaria acus, Wats. (PI. IX. fig. 2). 



Scalaria acus, Watson, Prelim. Report, pt. 15, Journ. Linn. Soc. Lond., 1883, voL xvi. p. 608, sp. 3. 

 „ „ Jeffreys, "Lightning" and "Porcupine" Moll., Proc. Zool. Soc. Lond., 1884, p. 139, 



sp. 15. 



Station 24. March 25, 1873. Lat. 18° 38' 30" N., long. 65° 5' 30" W. Off Culebra 

 Island, West Indies. 390 fathoms. Pteropod ooze. 



Station 73. June 30, 1873. Lat, 38° 30' N., long. 31° 14' W. West of Azores. 

 1000 fathoms. Pteropod ooze. Bottom temperature 39 - 4° F. 



Habitat. — North Atlantic, from 49 to 1254 fathoms (Jeffreys). 



Shell. — Small, compact, long, sharp, solidly ribbed, deeply sutured, with faint spiral 

 markings, and on the rounded base a strong thread. Sculpture: Longitudinals — there 

 are on the last whorl about 17, and on the first regular whorl about 15, strong, 

 raised, rounded ribs, which cross from suture to suture in the line of the axis, and 

 extend, though less strongly, to the base. Spirals — between the ribs there are traces 

 of feeble striae ; on the last whorl there is one sharpish thread, which comes out 

 exactly at the upper corner of the mouth, and encircles the base. Colour ivory-white. 

 Spire high, narrow, conical. Apex consists of three brownish-yellow, glossy, broad, 

 cylindrical Avhorls, of which the first is very short and rounded, the second short and 

 slightly conical, and the third high and cylindrical ; they have very fine, microscopic, 

 hardly raised, flexuous, longitudinal threads, and still finer spirals. Whorls 12 in all, 

 very much constricted at the suture both above and below, and somewhat flattened 

 in the middle ; after the apex they are of very slow and regular increase ; the last 

 is smallish, with a rounded base, within the contraction of which lies the basal thread. 

 Suhire wide and deeply impressed, oblique. Mouth broken. H. 0'22 in. B. 0*06. Pen- 

 ultimate whorl, height 0'037. Mouth, height 0-044, breadth 0'04. 



