MDLLUSCA. 479 



1 86 1. Pecten venustus Gabb, Synop. Moll. Cret. Form., p. 217 



(161). 

 1864. Pecten venustus Meek, Check List Inv. Foss. N. A., 



Cret. and Jur., p. 7. 



1868. Pecten venustus Con., Cook's Geol. N. J., p. 725. 

 1886. Pecten venustus Whitf., Pal. N. J., vol. i (Monog. U. 



S. G. $., vol. 9), p. 45, pi. 7, figs. 1-2. 

 1905. Pecten venustus Johns., Proc. Acad. Nat. Sci. Phil. 



(1905), p. ii. 



Description. "Shell quite small, seldom attaining a height of 

 more than five-eighths of an inch, and not commonly of 

 more than half an inch. Form nearly circular below the ears 

 and a little straightened on the cardinal slopes. Valves convex, 

 slightly inequivalve and erect, or not perceptibly inequilateral. 

 Cardinal line about half as long as the greatest width of the 

 valves, which is a very trifle less than the height. Auricula- 

 tions very unequal, distinctly separated from the body of the 

 shell. The posterior one is quite small and alike in each valve; 

 anterior large, ribbed on each valve, and provided with a mod- 

 erately distinct notch below in the right one. Right valve most 

 convex, marked by 17 to 19 elevated radiating ribs, which are 

 somewhat flattened on the top and are marked by fine trans- 

 verse striae. Interspaces narrow and deep. Many of the ribs 

 of this valve become duplicate below the middle of the valve. 

 Left valve depressed, convex, with narrow, sharply-elevated 

 ribs, which are separated by much wider interspaces, arid are 

 marked by comparatively distant elevated rugae. Many of the 

 wider interspaces have a thinner and smaller rib along their 

 middle below the center of the valve, corresponding to the dupli- 

 cated ribs of the opposite valve. 



On the interior of the valves the ribs are distinctly marked, 

 but much more strongly so along the margin of the shell. Cardi- 

 nal line marked by a single ridge on each side of the center nearly 

 parallel to the hinge-line in the left valve;, with corresponding 

 grooves in the right. Ligamental pit well marked." (Whitfield.) 



Remarks. This is one of the smaller species of Pecten recog- 

 nized in the Cretaceous faunas of New Jersey, and is a common 



