226 MALACOZOA, TROPIOPODA. LAMELLIBRANCHIATA, 



6. Pecten Pusio. Dwarf Scallop. 



Shell ovaie, or ovato-oblong, eqviivalve; both valves with 

 about forty alternately large and small, regular, compressed, 

 obtuse, somevy'hat undulated or nodose ribs, becoming more or 

 less scaly or spinous at the margin ; the ears very unequal, 

 one of them being almost obliterated ; the colovu-s various, 

 generally red or purplish and white or yellow. The greatest 

 diameter about three-fourths of an inch. 



This shell, which is very common in the outer Hebrides, and 

 on some of the western coasts of Scotland, appears to be of 

 rare occurrence in our district, where, on the coast of Buchan, 

 it was found in September, 1842, by Mr. Alexander Murray. 

 It seems to me perfectly distinct from either Pecten varius, or 

 Pecten distortus, but is much more nearly allied to the latter. 



Ostrea Pusio. Linn. Svst. Nat. 1146. — Pecten Pusio. Turton, 

 Brit. Biv. 215. PI. 17. f. 2^— Pecten Pusio. Flem. Brit. Anmi. 385. 



7. Pecten Island'icus. Icelandic Scallop. 



Shell suborbicular, subinequilateral, subequivalve, with 

 about forty crowded, narrow, convex, transversely lamelloso- 

 striate, subscabrous ribs, which subdivide as they proceed from 

 the umbones, so as to amount to a hundred and twenty or 

 more at the margins ; auricles unequal, similarly ribbed ; 

 lower valve externally yellowish- white ; upper variously tinged 

 with reddish-yellow, rose-colour, purple, or chestnut; inner 

 surface glossy, pearly, more or less ribbed, with very marked 

 impressions. Diameter four inches or more. 



Dead valves very common in deep w^ater, oft' the coast at 

 Aberdeen and Gamrie. No live individual hitherto found. 



Pecten Tslandicus. Flem. Brit. Anim. 385. — Pecten Islandicus. 

 Turt. Brit. Biv. 216.— Pecten Islandicus. Lamk. Syst. vi. 258 ; 

 Ed. 2. vii. 145. 



8. Pecten ohsoUtits. Striidate Scallop. 



Shell triangular-orbicvilar, thin, sub diaphanous, with the 

 valves little convex, one less so, with very obsolete longitudi- 

 nal ridges, and toward the margin numerous stria?, and mi- 

 nutely shagreened all over with longitudinal striula?, diverging 

 toward either side, and crossed by fainter striulre ; the ears 

 very unequal, the larger with a few prominent straight, longi- 

 tudinal, and numerous transverse, undulated striee ; the colour 

 various, whitish, pinkish, purple, brown, yellow, orange, trans- 

 versely banded, or spotted, patched or clouded with red, 



