224 MALACOZOA. TKOPIOPODA. LAMELLIBRANCHIATA. 



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

 129.— Pecteu maximus. Pemi. Brit. Zool. iv. 99. PI. 58. f. 61 ; Ed. 

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



2. Pkcten opercular is. 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, mere 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- 

 Avard 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, Gamrie, I3anfF, and Macduff. 



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

 Linn. Syst. Nat. i. 1147. — Pecten opercularis. Mont. Test. Brit. 

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

 liueatus. Penn. Brit. Zool. iv. 99. PI. 59. f. 61. iv. 222 —Pecteu 

 opercularis. Lamk. Svst. vi. 174; Ed. 2. vii. 142. — Pecten sub- 

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

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

 f. 30. 



3. Pecten vdriiis. 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 irregidarly 

 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 coloiu* various. 

 Diameter about two inches. 



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

 head and St. Fergus, in September, 1842. 



