MOLLTJSCA OE THE ' CHALLENGES ' EXPEDITION. 97 



been already used by Minister, in 1830, for a genus of Crustacea 

 — a change this in which it is to be hoped he will not persevere. 



2. Lacuna (Hela) maegaeitieeea, n. sp. 



St. 246. July 2, 1875. 36° 10' ST., 178° E. Mid-Pacific, E. of 

 Japan. Bottom temp. 35 0, 1 P. 2050 fms. Grey ooze. 



Shell. — High, conical, strong, white, smooth, with a spiral of 

 small beads just below the suture. Sculpture. There are many 

 unequal not strong lines of growth. There are, on the upper 

 part of each whorl, longitudinal puckerings stretching down from 

 the infrasutural row of beads, strongest on the last. The sur- 

 face is also finely scratched longitudinally. Spirals close, below the 

 suture there is a fine beaded thread with a slight spiral furrow 

 below it; there are many rounded, but very slightly raised spiral 

 threads ; the whole surface is also finely spirally fretted. Colour 

 dead white, procellanous. Epidermis. None preserved. Spire 

 high and conical. Apex broken. Whorls 3 (remaining), flatly 

 convex ; the last disproportionately long. Suture fine, but rather 

 deeply impressed. Mouth oval, pointed above and at the end of the 

 pillar, where it is also somewhat patulous, but the little expanded 

 angle there is hardly enough to suggest a canal. Outer lip rather 

 strong, very regularly curved from its junction with the body to 

 the point of the pillar. Pillar very much curved. Inner lip 

 carried across the body by a pretty strong callus, thin, sharp- 

 edged, and projecting on the pillar. Umbilicus not large, but a 

 well-marked and clearly defined furrow, whose exterior edge, 

 however, is not, like that of Lacuna, continuous with the outer lip. 

 H. 0-2. B. 0-13, least 01. Penultimate whorl 006. Mouth, 

 length 01, breadth 007. 



This is a much stronger shell than L. tenella, Jeffr., usually is ; 

 in form it is much higher in the spire, and narrower in proportion 

 to breadth ; the whorls are much more compressed, and the narrow 

 sharply impressed suture is much less deep ; the mouth is oval, 

 not round, and the sculpture of the surface is very different from 

 the hyaline gloss and texture of that other. It is unfortunate 

 that the apex, which is so characteristic a feature in L. tenella, is 

 broken in the ' Challenger ' specimen. 



Eossaetts (Adanson), Phil. 



Eossaeits ceeeus, n. sp. 



St. 184. Lat. 12° 8' S., long. 145° 10' E. East of Cape York, 

 Australia. Aug. 29, 1874. Bottom temp. 36° E. 1400 fms. 

 Grey ooze. 



