NATICA. 225 



Yar. 2. subovalis. Smaller, and of a somewhat oval shape, 

 with a longer spire ; fawncolour or whitish. 



Yar. 3. ventricosa. More globose, and short-spired. 



HABITAT : Everywhere, in sand, from the extreme 

 verge of low- water mark to the greatest depth within 

 the line of soundings. Var. 1. Widely distributed, but 

 not common. Var. 2. Shetland and west of Scotland, 

 in deep water (J. GL J.) ; Silverpits on the north-eastern 

 coast of England (Rich). Var. 3. Hebrides (J. G. J.). 

 Fossil in many of our quaternary deposits (Smith and 

 others) ; glacial and post-glacial beds in Norway, 0-440 

 feet (Sars). Its range, as a recent species, comprises 

 the North Sea from the Loffoden Isles southwards, the 

 western coasts of the North Atlantic, the Adriatic, and 

 both sides of the Mediterranean ; depths recorded from 

 various places 580 f. 



It glides swiftly along by means of its broad foot. 

 Mr. Dennis writes me word that it is a very ravenous 

 mollusk, and that, when placed in a basin of sea- water 

 with Scrobicularia alba or other small bivalves, it will, 

 as soon as night falls, pierce the shells and commence 

 devouring its prey. The spawn-case is not so tough and 

 leathery as that of N. catena \ one now before me mea- 

 sures an inch and a quarter in diameter, the circular 

 hole at the top being half an inch. The pad in very 

 young shells covers about one-half of the umbilicus, 

 although this latter part is nearly closed in some speci- 

 mens from Shetland. The ground-colour varies from 

 pure white to dark orange; occasionally the spots are 

 confluent, or they are replaced by broad bands, or else 

 by a white zone at the top of each whorl ; now and then 

 the upper whorls only are encircled by a single row of 

 spots ; and the streak outside the umbilicus is not unfre- 

 quently wanting. Specimens procured by Mr. Jordan 



LO 



