SOLARIELLA. 317 



low the suture, one at the periphery forming a carina, of which the 

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

 with beads like the first, defines the umbilicus, within which there 

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

 rather sharp threads, whose partings are twice as broad as themselves. 

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

 into 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, 

 closer-set, and moi-e irregular and interrupted, especially near the 

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

 white when alive, with a translucent calcareous layer through which 

 the nacre shines. Spire high, a little scalar. Apex small, a little 

 flattened, with the embryonic 1\ whorl barely projecting in the 

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

 a little tumid ; the preceding ones are a little roundedly shouldered 

 below the suture, flat on the contour angulated at the carina, and 

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

 rounded and hmgitudinally ribl)ed, suture is linear, but strongly, 

 not acutely defined by the perpendicular rise of the whorl above it 

 and the slight sloping shoulder below. Mouth round, scarcely 

 oblique, with a translucent porcelaneous edge, and pearly within. 

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

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

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

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

 narrowed within by the spiral ridge. Operculum of very many 

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

 gleaming flange. 



Alt. 0-32 in., diam. 0-32 in., least 0-28 in. Mouth, height Oi8, 

 breadth 0'18 in. (Watson.) 



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

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

 much more exquisitely sculptured, suture more impressed, base more 

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

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

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

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



