288 



TRIBE PECTINIDES, 



PLICATULA 



Inequivalve, not auricula ted, contracted towards the beaks, the 

 ventral margin rounded and more or less folded ; beaks unequal and 

 devoid of external ligament al areas. Hinge provided with two strong 

 teeth in each valve which enclose the ligament between them. 



P. Ramosa. Lam. 1. — Desh. Enc. Met. 3, p. 801. — Crouch 

 Int. t. 12, f. 5. — Spondylus Plicatus (in part), Dil. 210. — Ch. 

 f. 479,0. — Mawe Cone. t. 11, f. 2. — Oblong triangular, very 

 thick, white with ferruginous longitudinal lineoles ; folds large and 

 forked : hinge usually reddish, teeth striated. 1 J. America. 



P. Depressa. Lam. 2. — Desh. Enc. Meth. 3, p. 801. Oblong 

 oval or subtriangular, usually more or less depressed, white with 

 numerous small irregular brown spots which are chiefly upon the 

 folds, which latter are numerous small and usually only apparent 

 towards the margins ; hinge dark brown ; interior often stained 

 with the same colour especially upon the scars. 1^. America ? 

 Lamarck refers with doubt to Gualt. 104, F. which is probably an 

 Ostrea. 



P. Cristata, Lam, 3.— List. t. 210,/. U.—Ch.f. 481, &.— 

 Blain. t. 62, /. 2. — Henderson's Cuvier, t. 31, bis. f. 9. Oblong 

 wedge-shaped, whitish or ferruginous, adorned with chocolate 

 brown interrupted lines which are chiefly present upon the folds ; 

 these latter are large, deep, simple, angulated and few in number , 

 with frequently the appearance of being crested by the scales which 

 in perfect specimens surmount their angles in one or both the 

 valves. Var. Quite white. 1. America; W. Indies? 



P. Reniformis. Lam. 4. — Sloan Jamaic. Histor. t. 241, f. 20, 21. 

 Rounded, subarcuated, white, the folds simple, obtuse, squamiferous, 

 and diverging. 1 Jamaica. The Type in the French Museum is 

 rather depressed and has but seven or eight folds. 



P. Australis. Lam. 6. More or less rounded or ovate, 

 rarely if ever triangular, generally depressed and almost always 

 attached by the whole of the lower valve ; whi ish or ferruginous 

 with numerous dark dots or small spots ; surfacenot folded but with 

 very numerous close set squamular radiating riblets, which render 

 the margin slightly wavy but not plicated : inside uniform white. 

 Var. Quite white, lj. Philippines and Australia. 



P. Imbricata. Menke Moll. Nov. Holl. p. 35. — Rounded 

 wedge-shaped rather depressed, strong, varying from smoky brown 

 to bright orange, with numerous moderately subangular folds, some 

 of which (in the very large specimens only) are usually forked near 

 their termination, and all more or less armed with large vaulted 

 scales. If. 1;}. China; (deep water, sandy mud) W. Australia. 

 I am indebted tot he courtesy of the author, for an examination of his type 



