862 KEY. E. BOOG WATSON ON THE 



twisted swelling. Colour dull brownisli yellow, wliicli is a little 

 deeper on the tubercles. Spire higb, narrow, conical. Apex 

 slightly abrupt, consisting of 3| turbinated embryonic whorls, of 

 which the extreme tip is very small ; they are smooth and rounded, 

 but slightly keeled above the suture ; towards the first regular 

 whorl the carinating thread becomes double or triple, and a few 

 very oblique riblets appear. Whorls 9j, short, rounded, being 

 pretty equally constricted above and below ; the last is small, 

 being neither broad nor long; the base is short and conical, being 

 drawn out into a broad, lop-sided, slightly reverted snout, in which 

 lies the deep, wide, rounded nick of the anterior canal. Suture 

 very deeply impressed, rather oblique. Mouth semioval, obliquely 

 produced in front and abruptly truncated at the point ; it is 

 hardly angulated above. Outer lip has a feeble varix outside, 

 formed by a crowding at that point of the longitudinal riblets ; 

 the edge is sharp, flatly arched, scored internally with long nar- 

 row teeth, which are alternately stronger and weaker ; it is slightly 

 emarginated below the suture, prominent in front, and then re- 

 treats to the edge of the canal, and here alone it is patulous. 

 Inner lip short across the body, where the labial callus spreads 

 somewhat ; and there in the middle is a strongish little tooth ; 

 the junction of body and pillar is rather concave ; the pillar, 

 which is longish and somewhat swoln, is very obliquely cut 

 off and twisted, with a narrow rounded edge ; two strongish and 

 one or two feeble teeth cross it almost horizontally ; and it runs 

 out in front to a very fine, attenuated, but blunted point. H. 0'9. 

 B. 0-35. Penultimate whorl, height 0-16. Mouth, height 0-36, 

 breadth O'l?. 



This species is a good deal like P. iorneensis, Sow., from Borneo, 

 but is slightly slimmer ; the first whorls here are larger, the 

 suture is deeper, and between the spirals the shell is smoother. 

 In Sowerby's species, too, the upper angle of the mouth is much 

 more deeply sinuated, and behind this canal is an angulated callus, 

 the pillar is shorter and less sharply pointed, and there is no tooth 

 on the body ; the ribs in that species are stronger and closer set, 

 and are frequently developed into varices, of which, with the 

 exception of the feeble labral swelling, there are none in the 

 ' Challenger ' species. 



