154 BITTIUM. 



B. DELICATUM, Watson. PL 30, fig. 6. 



With about seventeen longitudinal ribs, separated by equal 

 grooves, abruptly terminating about half-way on the rounded body 

 whorl, spiral sculpture minute and faint, most prominent near the 

 suture ; translucent, glossy white. Length, 3'3 mill. 



Tristan da Cunha Is. 



B. GEORGIANUM, Pfeiffer. PL 29, fig. 92. 



Whorls with three strong spiral cingula? completely dominating 

 the distant longitudinal costulations ; rather thin ; yellowish white 

 with a few minute irregular fulvous spots, under a light yellowish 

 epidermis. Length, 5 mill. 



South Georgia IsL 

 B, TRICARINATUM, Pease. PL 30, fig. 9. 



Whorls turreted, rounded, with three strong spiral keels, longi- 

 tudinally plaited, suture well impressed, light yellowish brown. 



Length, 7'5 mill. 



Sandwich Is. 

 B. TURRITELLIFORMIS, Angas. PL 30, fig. 13. 



Rather thin, finely spirally ridged, interstices very minutely lon- 

 gitudinally striated ; whorls 10, the last keeled below, with smooth, 

 somewhat concave base ; light yellowish brown, inclining to reddish 

 purple on the upper whorls. Length, 8 mill. 



Port Jackson, Australia. 



B. PERPUSILLUM, Try on. PL 30, fig. 17. 



Brownish, whorls 9-10, with four spiral rows of granules, longi- 

 tudinally subplicate, base with five additional spiral riblets, suture 

 deep. Length, 6 mill. 



Japan. 



Described by Dunker as B. pusillum, preoccupied by Gould. 



B. ALUTACEUM, Gould. PL 30, fig. 10. 



Whorls strongly longitudinally ribbed, crossed by three spiral 

 ridges, forming three series of large tubercles, interstices deeply 

 pitted, suture deep ; brownish, the ridges of the last whorl spotted 

 with chestnut. Length, 6 mill. 



China Sea. 

 B. LAWLEYANUM, Crosse. PL 30, figs. 5, 94, 96. 



Whorls flatly convex, rounded at the suture, spirally distantly 

 grooved, bluish, white banded. Length, 10 mill. 



So. Australia, N. Zealand. 



