MOLLTJSCA OE THE ' CHALLENGER ' EXPEDITION. 113 



and strong. Inner lip unformed. H. - 147. B. - 06. Penulti- 

 mate whorl 0-02. Mouth, length 0-03, breadth 0-028. 



The sculpture of this species is after the fashion of the C. reti- 

 culatum, Da Costa, group, hut the form of the shell, its details 

 of sculpture, and the shape of the apex are very distinct. It is 

 not quite full-grown, so that the form of the base is not entirely 

 developed. 



13. Ceeithitjm (Bittium) Philomela, n. sp. 



St. 135. October 18, 1873. Nightingale Island, Tristao da 

 Cunha Islands. 100-150 fms. 



Shell. — Small, narrow, conical, blunt, outlines scarcely convex, 

 rounded at the periphery into the blunt square base, solid, dead 

 white, not glossy. Sculpture. Longitudinals — on the last whorl 

 there are 21 rows of rather coarse round tubercles, parted by very 

 narrow furrows ; these lines run very straight up the spire. 

 Spirals — on all but the first two whorls there are three very 

 equal spiral threads, which rise into tubercles as they cross the 

 longitudinals ; these threads do not appear on the first two 

 whorls ; they are parted by shallow furrows. The base of the 

 whorls is sharply but shallowly contracted, and in the bottom of 

 the contraction, above the suture, lies a small spiral, which is un- 

 dulated in crossing the longitudinals, and which, on the base, 

 forms a weak, feebly-tubercled circumferential border. Spire is 

 high, narrow, and has its outlines barely curved. Apex is blunt 

 and rounded, with a very minute oblique projection. Whorls 8, 

 just barely convex on the sides. Suture very minute and linear, 

 but well marked by the furrow at the base of the whorls. Mouth 

 squarish. Outer lip broken. Pillar straight, short, and broad. 

 Inner lip a layer of glaze crossing the body and twining round 

 the pillar. H. 0-128. B. 0-05. Penultimate whorl 0'025. Mouth, 

 length 003, breadth 0-02. 



This species, in its sculpture, belongs to the C. reticulatum 

 group. Than C. luscinice, which it resembles, it is much smaller, 

 more delicate in sculpture ; the apex is less squeezed down than 

 in that species. 



14. Cebithium (Bittittm) gemmatttm, n. sp. 



St. II. Jan. 13, 1873. Lat. 38° 10' N., long. 9° 14' W. Setubal. 

 470 fms. Glohigerina-ooze. 



Shell. — High, conical, not narrow for the genus, blunt, with 



