VARIETIES OF OYSTERS. 165 



Pectines of Stroma," and says, " I cannot think the odd, 

 strange tumbling the tides make there can contribute any- 

 thing to that frame ; yet, after all, I never see them in any 

 other place." 



It is the Ostrea sinuosa of Gmelin and the P. distortus 

 of Da Costa. In its younger state it is the P. midtistriatus 

 of Poli, and the P. Isabelle of Macgillivray, but not of 

 Lamarck. 



2. P. VARIUS, Linne. 



Ostrea van'a, Linn. Syst. Nat., p. 1146. P. varius, F. and 



H. 2, p. 273, pi. 50, f. i. 



BODY pale red, pink, brown, or yellow, sometimes 

 mottled with white or streaked with purplish-brown : 

 mantle broad-edged : cirri numerous, of unequal length but 

 mostly long and slender, arranged in four rows : ocelli 

 about 30, black, and smaller than in the last species : foot 

 rather large, thick, and white. 



SHELL transversely oval, much broader in front than 

 behind, nearly equilateral, rather solid and slightly glossy : 

 sculpture, 25-30 smooth and rounded ribs, which are equal- 

 sized ; the whole surface is covered transversely with fine 

 plates, which often form vaulted spines on the crests of the 

 ribs ; the interstices of the ribs are marked with minute 

 bifurcating striae : colour red, pink, yellow, purple, brown, 

 and rarely milk-white, with streaks or blotches variously 

 disposed : margins rounded in front and at the sides', and 

 notched or indented by the ribs, sloping abruptly to the 

 beak on each side from a little above the middle ; upper 

 side of the slope on the right hand of the lower valve 

 toothed or serrate, as in the last species : beaks prominent : 

 ears unequal and formed as in P. pusio ; the right-hand one 

 of the lower valve projects beyond and slightly overlaps 



