418 EEY. E. BOOG WATSON ON THE 



bute to a var. cariosa, the concave furrow below the suture is 

 almost absent, and the aspect of the shell is somewhat differ- 

 ent ; but both these features are perhaps a mere deception of 

 the eye caused by the rubbing down of the ribs, which are much 



wasted. 



21. Pletjeotoma (Detllia) btjlbacea, n. sp. 

 St. 169. July 10, 1874. Lat. 37° 34' S., long. 179° 22' E. 

 N.E. from New Zealand. 700 fms. Grey ooze. Bottom tempera- 

 ture 40°. 



Shell. — Broadish, conical, sharply keeled, with a shortish con- 

 tracted base and a short snout, short narrow ribs, and spiral 

 threads, a bulbous apex, strong, porcellaneous. Sculpture. Longi- 

 tudinals — below the sinus-area and about one third down the whorl 

 from the suture arise, not quite abruptly, ribs slightly tubercled at 

 the top, straight, direct, narrow, and parted by shallow furrows 

 about twice their breadth ; they become feeble toward the lower 

 suture ; on the last whorl they do not continue to the base, 

 and become broader and weaker toward the mouth : there are 

 eleven on the last and penultimate whorls ; on the first infraem- 

 bryonic whorl there are about seventeen, crowded, sharp, scarcely 

 curved and oblique. The lines of growth are numerous and 

 unequal ; in the sinus-area they are sharp and delicate, on the 

 rest of the shell coarse and puckered. Spirals — marginating 

 the suture at the top of each whorl is a narrow scarcely swollen 

 band ; below this the sinus-area is very finely, almost microscopi- 

 cally, scratched ; and this scratch-sculpture is continued, though 

 less distinctly, on the rest of the surface. The projection of the top 

 of the ribs forms a sharp keel. The rib-area is crossed by five 

 coarsish threads, which rise into small tubercles on the ribs ; one 

 or two smaller threads come in between the lines of these spi- 

 rals. The same sort of threads, but less distinct, are found on 

 the base ; those on the pillar and snout are a little more distinct. 

 Colour dull porcellaneous white. Epidermis quite gone. Spire 

 rather short, conical, very slightly scalar, cylindrical toward the 

 top. Apex two smooth embryonic whorls, swollen and roundedly 

 pressed down, with a deepish suture, rather more prominent than 

 the regular whorl which follows. Whorls 6£, short, of rather 

 rapid increase ; the last large relatively to the rest ; from the 

 suture to the ribbing they are concavely shouldered. The pro- 

 jection of the tubercles at the top of the ribs forms a carination. 





