16 LITTORINlDiE. 



rately solid, semitransparent and rather glossy : sculpture, 

 numerous fine longitudinal striae, which are crossed by stronger, 

 fewer, and rib-like transverse striae, forming by their inter- 

 section an open network ; the longitudinal striae are gently 

 curved, and they do not reach the base, although there are 

 sometimes traces of them below the periphery ; the labial rib 

 is strong but not thick, and traversed by the spiral striae only ; 

 of these striae 3 or 4 are more conspicuous than the rest on the 

 body-whorl ; examined microscopically the whole surface is 

 covered with extremely close-set spiral lines ; and even by the 

 aid of a Cocldington the top whorls may be seen to have a few 

 spiral rows of salient and reentering angles, which last prefigure 

 the cancellated structure of the adult shell : colour clear-white : 

 spire ending in a blunt and almost truncated point : whorls 5, 

 convex, gradually enlarging, the last exceeding all the others 

 put together in the ratio of nearly 5 to 3 when viewed with 

 the mouth upwards, but when placed with the mouth down- 

 wards these proportions are reversed ; the apex is compressed : 

 suture very deep and channelled : mouth more round than oval, 

 scarcely expanding outwards : outer lip thin, incurved above : 

 inner Up slightly reflected, and having behind it a more or less 

 distinct umbilical chink. L. 01. B. 0*065. 



Habitat : Sandy ground off Unst (the most northern 

 of the British Isles), at distances of about 8 and 30 

 miles from the land, in 70-85 f. ; rare. Norway (Lill- 

 jeborg and Malm ; the locality mentioned to me by the 

 latter is Eggersbank, and the depth 150 f.) ; North 

 America (M 'Andrew, by whom it was received from a 

 correspondent) . 



The dried remains of the animal exhibit an orange 

 tint in the region of the liver. Although of the same 

 size as R. punctura, this is of a somewhat turreted shape, 

 clear-white, and nearly transparent, the reticulation is 

 much less crowded (resembling open lacework), the 

 spiral striae in the middle are more prominent, the suture 

 deeper, whorls more gradually increasing, and the apex 

 is blunt and marked with a Vandyke pattern instead of 

 having rows of punctures. The present case exemplifies 



