REPORT ON THE GASTEROPODA. 357 



by a broadish flat band, below which on the extreme point of the base is a series of 4 sharp 

 narrow threads and furrows, followed by about as many more, smaller and more crowded 

 on the snout. Colour porcellanous white, glossy, with a buff tip. Spire long relatively 

 to the shell, shortly scalar, convexly conical. Apex: the extreme tip is broken, but had 

 evidently been very small ; two whorls remain, rounded, high, conical, parted by a distinct 

 suture, buff-coloured, minutely straight-barred above and reticulated below. Whorls 5, 

 below the embryonic apex ; probably about 9 in all ; the rows of infrasutural tubercles 

 give them a minute double keel above with an oblique slope at this part, below which 

 they are cylindrical, or very slightly contracted to the lower whorl : this contraction is 

 distinct on the last whorl, which is very small. The base is rounded and contracted, 

 and ends bluntly in a triangular snout with a slightly reverted point ; the advance of the 

 pillar on the left side is rather more than one would have expected. Suture small, but 

 very strongly marked. Mouth ovate, contracted and angulated above, produced into the 

 broad, open, and oblique canal below. Outer lip confused by having been broken and 

 mended ; but apparently thickened and probably marginated above, very flatly curved 

 with great regularity from end to end ; the edge runs very straight, with little of promi- 

 nence, and forms a very slight and shallow rounded sinus near, but not quite close to, the 

 suture, from which it seems to be separated by an extension of the upper beaded line. 

 Inner Up broad, formed by a glossy pad above, and below it is slightly excavated into the 

 substance of the shell. It runs straight out along the pillar to the very point, where it 

 meets the very oblique, twisted, and thickened edge : the pillar is thus very short, stumpy, 

 and obliquely cut off in front, reminding one of a Nassa; and its whole point is a little 

 twisted and reverted. H. 0"31 in. B. 0'13. Penultimate whorl, height - 06. Mouth, 

 height 0-13, breadth 0-07. 



11. Clathurella circumvoluta (Watson), (PI. XXI. fig. 1). 



Pleuroioma (De/rancia) circumvoluta, "Watson, Prelim. Report, pt. 10, Journ. Linn. Soc. Lond., vol. xv. 



p. 465. 



Station 24. March 25, 1873. Lat. 13° 38' 30" N., long. 65° 5' 30" W. North of 

 Culebra Island, West Indies. 390 fathoms. Pteropod ooze. 



Shell. — White, strong, with a high, scalar, small, buff-tipped spire, an excessively 

 small body, and a contracted conical base. Sculpture : Longitudinals — there are on each 

 whorl about 14 slight, narrow, ridge-shaped, round-topped, oblique and slightly irregular 

 riblets ; they rise sharply in obscure tubercles below the sinus-area, and die out at the 

 point of the base ; they are parted by shallow rounded furrows of more than twice their 

 breadth. The sinus-area is scored by minute cusp-like remote bars, which generally are 

 not continuous, but are interrupted about the middle, and are more numerous on the 

 lower than the upper half of the area : the lines of growth are extremely fine. Spirals — 



