REPORT ON THE GASTEROPODA. 307 



edge leaves a small, shallow, umbilical furrow. Operculum typical, having the nucleus 

 apical and being curved ; thin, rather strongly marked with the lines of growth, and 

 having on its outer face a small, prominent, but not thickened bank or rising in the 

 middle from end to end. H. L42 in. B. 0'45. Penultimate whorl, height 0*23. Mouth, 

 height 0-6, breadth 0-24. 



The specimen of this fine species obtained from off Albany Island is full-grown, and is very 

 markedly broader than the other ; but in all other respects they are identical. Otherwise like 

 Plcurotoma intemi-pta, Lam., in form, it has a longer pillar. It has some resemblance in shape to 

 Plcurotoma rosaria, Reeve, but in all details is most distinct. 



37. Pleurotoma (Drillia) climacota, 1 Watson (PI. XVIII. fig. 1). 



Pleurotoma (Drillia) climacota, Watson, Prelim. Report, pt. 9, Journ. Linn. Soc. Lond., vol. xv. 



p. 428. 



Station 172. July 22, 1874. Lat. 20° 58' S., long. 175° 9' W. Inside the reef, 

 Tongatabu. 18 fathoms. Coral mud. 



Shell. — Strong, biconical, with a high, pointed spire, and a short, lop-sided, but truly 

 conical base, reticulated with ribs and spirals, and with a constricted band below the 

 suture. Sculpture: Longitudinals— there are about 15 or 16 rather narrow, sharpish ribs 

 on each whorl, with intervening furrows of rather greater breadth ; they cross the whorls 

 with very little obliquity from suture to suture, and on the last extend to the very point ; 

 a few of them bifurcate on the base ; the lines of growth are very slight. Spirals — below 

 the suture is a band about -h of an inch high, which constricts the upper part of the 

 whorl to the breadth of the base of the one above ; this forms the sinus-area : below this 

 is a shoulder on which the ribs project. There are about sixteen or seventeen rounded 

 spiral threads, which are feeble in the furrows, but rise into small rounded tubercles on 

 the ribs ; they are parted by shallow flat furrows of about the same breadth : of these 

 spiral threads there are four on the penultimate whorl ; and they diminish in number up 

 the spire. The whole surface is very finely spirally striated ; and there are microscopic 

 granulations besides. Colour white. Spire very regularly conical, but distinctly scalar 

 from the angular projection of the shoulder. Apex somewhat worn, but small, 

 apparently consisting of two conical, rounded, embryonic whorls with a fine sharp 

 suture. Whorls 10 in all, rather high, of very regular and slow increase, angulated by 

 the constriction and the shoulder below it. The upper whorls are cylindrical below the 

 shoulder ; but the body -whorl contracts almost at once, and on the base does so very 

 rapidly and with very straight lines, so that this whorl is very small. Suture very small 

 and faint. Mouth small, narrow, elongately oval. Outer lip broken : the sinus lies 



1 x\ifj,uxuro;, scalar. 



