228 MAliACOZOA. TROPIOPODA. LAMELLIBRANCHIATA, 



First found in the Winter of 1841, by Mr. Leslie, at Aber- 

 deen and the Cove. 



Pecten similis. Laskey, Wern. Mem. i. 387. PL 8. f. 8, 8. 

 Pecten similis. Flem. Brit. Anim. 385. 



11. Pecten tumldus. Unequal-sided Scallop. 



Shell suborbicular, flattish, thin, fragile, smooth, semitrans- 

 parent toward the margins, opaque-white in the centre ; the 

 valves almost equal, with one side bulging ; umbones nearly 

 central, pointed, hinge-line straight ; auricles about equal in 

 length, smooth, being but faintly marked with growth-lines ; 

 colour white. Diameter a quarter of an inch. 



This species can hardly be confounded with either of the 

 two last, unless by persons who may suspect all little smooth 

 pectens to be the same. All the specimens seen by me have 

 an opaque white central portion, the margin transparent, the 

 small auricle of the upper valve rounded, the auricles not 

 striated longitudinally, and one of the sides very prominent. 

 Small specimens of the same size as Turton's figure agree per- 

 fectly with it, and, although the circumstance is not mentioned 

 in the description, it will be seen to be white in the centre. 



First found by Mr. Alexander Davidson in the stomach of 

 a haddock, Aberdeen, in the Winter of 1841 ; by me, on the 

 beach there, in October, 1842. 



GENUS 2. LIMA. RASP-SCALLOP. 



Shell free, regular, oval or oblong, equivalve, aniso- 

 meral, divergently costulate or striate; umbones very 

 small, pointed, direct, not contiguous. Cardinal space 

 elongated, with a straight margin, and having externally 

 a somewhat triangular concave depression. Ligament 

 external, trigonal, received by the cardinal pits. 



1. Lima Loscombi. Loscombe's Rasp-Scallop. 



Shell obliquely oval-oblong, tumid, thin, brittle, pellucid ; 

 with the hinge auriculate ; the umbones small, projecting a 

 little beyond the margin ; the valves equal, with fine concen- 

 tric striulse, and numerous slightly undulated, radiating cos- 

 tulae, with intervening striae, generally two or three between 

 each pair ; the colour hyaline-white ; the inside glossy, with 

 the radiating markings apparent. Length in the direction 



