transverse and straight; the beaks contiguous; 

 hinge toothless, the cardinal cavity entirely internal, 

 triangular, and receiving the ligament. 



* Ears equal or nearly so. 



P. MAXIMUS. Pen. 4. p. 219. t 62. Lam. 1. 

 P.p. 383. Turt. B.p. 207. Ch.f. 585. Mont. p. 

 143._OsTREA M. Lin. 1144. List. t. 163. /. 1. 

 Knorr. 2. t. 14. f. l.E. t. 285. /. I. Don. 2. t. 

 49. Lin. T. S.p. 96. Dor. Cat. p. 37. t. 9./. 3. 

 D. p. 247. Turt. D. p. 128. P. VULGARIS. Da. 

 Cos. t. 9. f. 3. Suborbicular, inequivalve, one valve 

 being convex white and tinged with yellow towards the 

 beaks, the other flattish concave towards the beaks and 

 usually brownish red, or white variegated with pink or 

 brown ; about fourteen radiating rounded ribs. 4 or 5. 

 The common scallop. 



P. OPERCULARIS. Pen. 4. p. 221. t. 63. /, 2. 

 Mont. p. 145. Lam. 34, F. p. 383. Turt. B.p. 

 209. E. t. 112./. 2. OSTREA O. Lin. 1146. Dor. 

 Cat. p. 38. t. 9.f. 1,2,4,5. D. p. 266. Turt. D. p. 

 129. f P. PICTUS. Da. Cost. t. 9.f. [,2,4,5.) List. 

 t. 190./. 27. Knorr. 2. t. 2. /. 2,3. Suborbicular, 

 the upper valve the more convex, with from eighteen to 



