278 TRIBE PECTINIDES. 



on each side much narrower and serrated across : lower valve 

 with but twelve ribs, the lateral alone serrated. 1-J. . 1. Ceylon and 

 Singapore. 



P. Radula. Lam. IZ.—Sow. Th.f. 154,6.-- E. t. 208. /. 2.-— 

 Ostrea R. Lin. 1145.— W. t. 10./. 11.— D. p. 251.-— List. t. 175. 

 /. 12.— Ch.f. 599,0.— Knorr. 5. t. 9./. 4. Subtriangular, thick, 

 compressed, scabrous, with radiating sulci, anteriorly subelongated 

 at the margin, the sides flattened ; ears nearly equal, obtuse, roughly 

 ribbed, emarginated at the base ; pale yellowish spotted with brown 

 or black, sometimes nearly covered with brown bands, with from 

 nine to twelve elevated squarish ribs, which are thick, radiately 

 grooved and concentrically striated, the interstices broad and sul- 

 cated ; hinge obliquely plicated. 3£...3|-. Ceylon. 



P. Velutinus. Sow. Th.f. 31. Suboval, rather compressed, 

 equilateral, with fine radiating striae, rather swelled at the mar- 

 gin ; the ears nearly equal, striated ,* hinge obliquely plicated ; 

 reddish fawn coloured, with variegated angular bands of white 

 margined with brown, with five thick and rounded ribs which 

 gradually become fainter. lj...3^. Macassar. 



P. Noduliferus. Soiv. Th. f. 38, 39, 94. Subtriangular, 

 rather compressed, with radiating striae, equivalve ; ears radiately 

 sulcated, the posterior slightly the larger j hinge obliqely plicated ; 

 red with angular spots, (clouded inside) and eight thick rounded 

 and nodulous ribs which are internally plicated at the margin. 

 1,46. . 1,35 Not unlike Corallinoides. 



P. Subplicatus. Sow. Th.f. 37, 72, 73, 81. Equivalve, sub- 

 triangular, subequilateral, depressed, with radiating stria? ; ears 

 large, striated, the anterior the larger and nearly rectangular ; 

 hinge obliquely plicated ; light cream coloured, with angular 

 patches of dark blackish brown or brick red, with five broad 

 scarcely elevated ribs, the interstices very broad; inside brown 

 particularly about the hinge. 15. . 1^. Amboyna. 



P. Plica. Lam. 19.— Sow. Th. f. 237,8,9.— Ostrea P. Lin. 

 1145.— D. p. 252.— Ch. f. 598 & 2041.— W. t. 10. /. 13. 

 Rounded-trigonal, ventricose, thick, with radiating striae, flattened 

 near the umbones ; ears small, nearly equal, obtuse, striated, con- 

 tracted at the sides ; variable in colouring, usually with large patches 

 of a dark colour on a light ground, the three central ribs thick 

 and rounded, the two on each side of them much smaller ; in- 

 ternally with tooth-like plaits, the hinge brown and plicated. 

 1-A-..IJ-. Nicobar, Ceylon, China. 



P. Corallinoides. D. Orb. Mol. Can. p. 102. — Sow. Th.f. 3, 4. 

 Rounded, ventricose, equivalve, with radiating striae, anteriorly 

 produced, red, clouded, the ribs alternately paler ; ears sulcated, 

 obtuse, the posterior the larger, emarginated at the base, hinge 



