SOL A RI ELL A. 317 



o\v the suture, one at the periphery forming a carina, of which the 

 seads are much smaller and closer set, sometimes evanescent; one, 

 *vith beads like the first, defines the umbilicus, within which there 

 s a strong spiral ridge ; and the whole surface is covered with fine 

 *ather sharp threads, whose partings are twice as broad as themselves. 

 3f these finer spirals, the one which meets the outer lip often rises 

 nto prominence and defines the base, while another above the carina 

 sometimes stands out more strongly and more beaded than the rest. 

 Longitudinals the whole surface is close-set with these, which are 

 crossed by the spirals, than which they are broader but less sharp, 

 jloser-set, and more irregular and interrupted, especially near the 

 ipper line of tubercles and near the umbilicus. Color a bluish 

 vhite when alive, with a translucent calcareous layer through which 

 ;he nacre shines. Spire high, a little scalar. Apex small, a little 

 lattened, with the embryonic 11 whorl barely projecting in the 

 iiiddle. Whorls 6-7, the last is of rapid increase, full rounded and 

 i little tumid ; the preceding ones are a little rounded ly shouldered 

 )elow the suture, flat on the contour angulated at the carina, and 

 slightly contracted into the sutur \ ; the apical whorls are simply 

 ounded and longitudinally ribbed, suture is linear, but strongly, 

 lot acutely defined by the perpendicular rise of the whorl above it 

 md the slight sloping shoulder below. Mouth round, scarcely 

 )blique, with a translucent porcelaneous edge, and pearly within. 

 Duter lip not descending, sharp ; its inner edge is beveled outwards 

 it the expense of the pearly layer. Pillar-lip bends over the um- 

 )ilicus, is a little reverted, and expands into a tooth at the intra- 

 imbilical ridge. Umbilicus funnel-shaped, wide, pervious, but 

 larrowed within by the spiral ridge. Operculum of very many 

 i arrow whorls, which on their outer edge over lap as a narrow 

 gleaming flange. 



Alt. 0'32 in., diam. O32 in., least 0'28 in. Mouth, height 0'18, 

 Breadth 0- 18 in. (Watson.} 



This is a much larger species than Trochus (Margarita) cinereus, 

 Jouth. ; from the North Atlantic, much higher, much more conical, 

 iiuch more exquisitely sculptured, suture more impressed, base more 

 iiimid and not angulated at the edge, umbilicus larger. Than 

 Frochus (Margarita) amabilis Jeffr., it is, of course, still larger, less 

 xmical, less angulated, the sutural impression is not like a rounded 

 'ouged-out line as it is there, the base is not flattened, and the whole 



