258 POSTSCRIPT. 



thing more than that it has undulated, remote, oblique co- 

 lored markings. 



Nerita glaucina. p. 124. 



Our figures 71 and 72, were by mistake given to N. Can- 

 rena, and should be removed to this species. 



Ostrea Islandica, Northern Scallop. 



Lister, pi. 1057. f. 4 SAaw, Nat. Miscell. pi. 978, 987. 



Ostrea cinnabarina. Dillwyn, p. 256. 



Shell orbicular, or inclining to oval, thin, transparent, 

 flattish, equivalve, with from thirty-five to forty fine longi- 

 tudinal ribs, which are mostly cloven at some distance be- 

 low the hinge, and frequently divided into three near the 

 front margin, forming a numerous and crowded assemblage 

 of ribs round the circumference, generally appearing as if 

 they were alternately smaller ; these are a little rough with 

 raised vaulted scales, especially about the margin : color 

 pale chesnut, whitish, or pink, variously depicted with rose- 

 color, carnation, or deep-purple red, and more or less di- 

 stinctly marked with darker transverse semicircular bands, 

 and five paler longitudinal rays ; the under valve white, or 

 slightly colored : ears scaly, and strongly ribbed trans- 

 versely ; the smaller one about half the length of the other, 

 which is rounded and deeply sinuated or emarginate under 

 the hinge : inside white, or tinged with rose-color towards 

 the hinge, glossy, perlaceous, strongly striate or ribbed, 

 with the margin finely serrate by the projection of the nu- 

 merous ribs : length three inches and three-quarters ; 

 breadth three and a half. 



Young shells are of a more oval shape, without scales, 

 and the ribs are few of them divided, and consequently not 

 so numerous and crowded about the margin. In this stage 

 they much resemble the O. varia in shape ; but the valves 

 are flatter, and the ears are not so disproportionate. 



Since our sheets describing this family have been printed 

 off, a fresh and perfect series of this very fine and beautiful 

 species have come before us, from an inch long to the size 

 above mentioned. Those which we have in our cabinet 

 were quite flexible at the cartilage, and had more or less 

 the remains of the fish in them 5 and, as we understand, 



were 



