234 Dr. J. Gwyn Jefiieys on 



I regard S. aspera of Philippi as a variety of the present 

 species. The height of the spire is an unreliable character. 



Scissurella tenuis *, Jeffr. 



Shell forming a depressed cone with an expanded base, 

 sloping to the periphery and slit, very thin, scarcely semi- 

 transparent, and rather glossy : sculpture^ extremely nume- 

 rous and fine curved longitudinal striaj, and equally numerous 

 and fine concentric or spiral striae, which by their intersection 

 cause a regular but minute cancellation ; the concentric striae 

 at the base are stronger and more distinct than the longitudi- 

 nal striae ; the sculpture is of course interrupted by the peri- 

 pheral slit and groove : colour pearl-white : spire greatly 

 depressed : whorls 5, somewhat flattened below the suture ; 

 the last enormously exceeds in size all the others put together : 

 slit central, long and broad : groove also broad, marked across 

 by regular but rather distant curved strijB ; edges sharp and 

 upturned : mouth obliquely oval : outer lip thin : inner lip 

 folded back and curved : pillar nearly straight, having a 

 twisted fold in front of the umbilicus^ which is small and 

 narrow. L. 0-25. B. 0-2. 



Station 12, 1450 fms. ; two dead and imperfect specimens. 



This differs from 8. crispata and its varieties in its depressed 

 shape, thinner texture, more delicate sculpture, the larger size 

 of the last whorl in comparison with the others, the pillar 

 being furnished with a fold, and in its narrower umbilicus. 



TrochidaB. 



Cyclostrema hasistriatum f, Jeffr. 



Shell somewhat globular, resembling in shape a small 

 Trochus of the Margarita section, thin, semitransparent, and 

 glossy : sculpture^ more or less numerous and fine spiral striae, 

 wliich cover diff'erent parts of the surface in difterent speci- 

 mens ; sometimes they occur on the base only and encircle 

 the umbilicus, being in that case stronger ; at other times the 

 upper whorls have a single ridge-like stria at the top, so as 

 to give an angulated appearance to the crown or summit ; in 

 the young the umbilicus is surrounded by a strong keel-like 

 stria : colour whitish : sp)ire raised : whorls 4, swollen ; the 

 last occupies three fourths of the spire ; the first or topmost 

 whorl is rounded and blunt : suture deep : mouth circular, 

 slightly angular above : umbilicus rather narrow, but deep : 



* Thin. t Striated at the base. 



