538 BULLION. 



where its course is slanting and subrectilinear, and recedes 

 considerably below, where it is greatly arcuated and dis- 

 posed to expand. The white pillar lip, whose internal 

 gyration is visible to the extreme apex, projects at its free 

 edge, is not very broad, and is much incurved. Indi- 

 viduals attain to two inches and a half in length, and an 

 inch and a half in breadth. "" 



The animal is bulky, but not longer than the shell 

 posteriorly. It is entirely of a pinkish or orange-tinted 

 white. The capital disk is quadrate and very large, the 

 lateral lobes comparatively small. There are no traces of 

 eyes. The shell is completely exposed. 



This mollusk lives, chiefly on sandy ground, at various 

 depths between one and fifty fathoms. It is distributed 

 all through the British seas, but not always plentifully, 

 and in some of our provinces it is local. It ranges through 

 the European seas. As a fossil it probably dates its 

 history from the coralline crag epoch. 



PHILINE. AscANius. BULL^A. Lamarck. 



Shell thin, fragile, smooth, frosted, striated or punctated, 

 translucent, loosely convolute, suborbicular or ovate, aper- 

 ture very wide and open, outer lip patulous ; spire small, 

 often concealed. No operculum. 



Animal investing the shell, large, slimy ; capital disk 

 oblong or subquadrate, no eyes nor tentacula ; lateral lobes 

 developed ; foot not produced posteriorly ; branchial plume 



* Mr. Jeffreys infonns U8, tliat the li. zonaria of Turtoii (Mag. Nat. Hist, 

 vol.vii. p. 352, copied in Brit. Marine Conch, p. 140, and Brown, 111. Conch. 

 G. B. p. 5G), described from a specimen in the collection of Mr. Clark (which 

 passed into his hands along with Turton's), was merely constituted from the fry 

 of lignana. We have never seen a specimen, however, that could truly be said 

 to be encircled by minute raised granular dots. 



