HELCION. 243 



versely triangular : mouth minutely scalloped or puckered : 

 tentacles slender : eyes small : gills of a whitish colour : foot 

 oval, equally broad at both ends ; sole yellowish- white, edged 

 with a narrow brown line. 



SHELL resembling the " cap of liberty," convex, semitrans- 

 parent, and glossy : sculpture, sometimes very slight and in- 

 distinct angular lines, which radiate on all sides from the beak, 

 and vary in number and regularity ; the surface, however, is 

 frequently quite smooth ; it is covered with numerous and 

 close-set microscopical concentric striae, which in old shells are 

 raised into distinct marks of growth : colour yellowish-brown of 

 different shades passing into horncolour, and adorned with 

 from 25 to 40 narrow bright blue streaks on a brown ground ; 

 these streaks radiate from the beak, and are more or less in- 

 terrupted ; crown marked with a dusky spot and occasionally 

 with a short linear ray of the same colour : beak sunk below the 

 level of the crown and inconspicuous : mouth oval : margin 

 compressed at the sides, even and smooth : inside shining and 

 polished, as if highly glazed, opalescent or lilac in adult shells. 

 L. 0-8. B. 0-6. 



Yar, Icevis. Shell more or less solid, opaque, compressed, and H * ' 

 expanded. Patella Icevis, Pennant, Brit. Zool. iv. p. 144, 

 pi. xc. f. 151. 



HABITAT : On LaminariG at low water (and as deep 

 as 15 f., Forbes and M f Andrew), on all our coasts ; the 

 young are sometimes also found on the under side of 

 large stones which are uncovered at spring tides. 

 Mr. James Smith has enumerated it as fossil from Dal- 

 muir, Ayr, Banff, and Ireland ; and Sars, from the newer 

 glacial formation near Christiania, at a height of 100 ft. 

 Living in the Faroe Isles (Mb'rch) ; North Cape 

 (Danielssen) ; Scandinavia, from the shore to 20 f. 

 (Brander, Loven, and others) ; Heligoland (Frey and 

 Leuckart); coasts of France (De Gerville and others); 

 Vigo, 8 f., and Cascaes Bay, 15-20 f. (W Andrew); 

 Mediterranean (Linne); Sicily (Maravigna); Mogador, 

 littoral to 3 f. (M f Andrew and R. T. Lowe) . The variety 



M 2 



