224 MALACOZOA. TROPIOPODA. LAMELLIBRANCHIATA. 



Anim. 383. Pecten maximus. Lamk. Syst. vi. 163; Ed. 2. vii. 

 129. Pecten maxiinus. Penn. Brit. Zool. iv. 99. PI. 58. f. 61 ; Ed. 

 2. iv. p. 219. PI. 62. Pecten maximus. Mont. Test. Brit. 143. 



2. Pecten opercularis. Common Scallop. 



Shell nearly orbicular, inequivalve ; the lower valve more 

 convex, with twenty-two convex subcarinate ribs, which, with 

 their concave interstices, are longitudinally striate, and trans- 

 versely lamelloso-striate ; upper valve convex, with twenty-four 

 convex ribs, more rounded than the lower, their intervals more 

 finely striate ; the auricles rather unequal, divergingly costato- 

 rugose, and concentrically lamelloso-striate ; one of those of 

 the upper valve with a deep notch between it and the margin 

 of the shell, and along the groove is a series of small teeth ; 

 internal surface glossy, with flattened ribs, more distinct to- 

 ward the margin ; lower valve externally variegated with red, 

 brown, and white ; upper paler ; interior white. Diameter 

 three inches or more ; but the largest that I have seen from 

 our coasts measures only two inches and one-twelfth in length, 

 two and a fourth in breadth. Variations as to colour are end- 

 less ; sometimes the inside also tinged. Young shells have 

 the ribs carinate, and smoothish on the ridge. 



In deep water, on hard ground, off the coast at Aberdeen, 

 not uncommon ; dead shells abundant ; also at Cruden, Peter- 

 head, Gainrie, Banff, and Macduff. 



Pecten opercularis. Test. Brit. Biv. 209. Ostrea opercularis. 

 Linn. Syst. Nat. i. 1 1 47. Pecten opercularis. Mont. Test. Brit. 

 145. Pecten opercularis. Flem. Brit. Anim. 383. Pecten 

 lineatus. Penn. Brit. Zool. iv. 99. PI. 59. f. 61. iv. 222 Pecten 

 opercularis. Lanik. Syst. vi. 174; Ed. 2. vii. 142. Pecten sub- 

 rufus. Penn. Brit. Zool. iv. 102. PI. 61. f. 64. Pecten tenuis sub- 

 rufus, maculosus, circiter 20 striis. Lister. Anim. Angl. 185. PI. 5. 

 f. 30. 



3. Pecten vdrius. Variegated Scallop. 



Shell roundish, somewhat ovate, nearly equivalve ; the 

 lower valve a little more convex ; both with about thirty-two 

 rounded, somewhat compressed ribs, which are irregularly 

 elevated into concave laminiform prickles, the grooves finely 

 reticulated ; the auricles very unequal, one of those of the less 

 convex valve separated by a deep incision ; the colour various. 

 Diameter about two inches. 



Found by Mr. Alexander Murray, on the coast of Peter- 

 head and St. Fergus, in September, 1842. 



