594 SYSTEMATIC PALEONTOLOGY 



Amusium conradi Whitfield, 1885, Mon. U. S. Geol. Survey, vol. ix, p. 52, 



pi. vii, figs. 8-10. 



Pecten conradi Johnson, 1905, Proc. Acad. Nat. Sci., Phila., p. 12. 

 Pecten conradi Weller, 1907, Geol. Survey of New Jersey, Pal., vol. iv, p. 



474, pi. 1, figs. 1-4. 



Description. " Shell small, seldom exceeding half an inch in height ; 

 erect-ovate, becoming more elongate proportionally with increased 

 growth. Valves slightly convex. Hinge short, from half to two-thirds as 

 long as the width of the body of the shell, strongly and distinctly aurieu- 

 lated. Beaks of the valves small and pointed, and the cardinal slopes long, 

 straight or slightly concave, extending to near the point of greatest width 

 of the body of the shell. Left valve smooth or but faintly marked by fine 

 concentric lines, and a few (five or six) very faint radii. Ears smaller 

 than in the opposite valve, both sloping toward the beak on the outer mar- 

 gin. Right valve marked with crowded concentric folds or elevated lines ; 

 also by five or six radiating lines ; not always present. On most specimens 

 there are distinctly rounded concentric folds or varices, but on some they 

 are thin, sharp lines; always more crowded and usually finer toward the 

 front, in adult specimens. Ears very distinct; that of the posterior side 

 sloping toward the beak and the anterior one rounded at the extremity 

 and deeply notched. 



" This shell is very closely allied to P. simplicus Conrad, but differs in 

 being more elevated and in the surface markings, that one being generally 

 smooth or imperceptibly marked. In making these comparisons I have 

 used a number of each valve of the present species from New Jersey, and 

 a fine series of A. simplicum from the typical locality, Eufaula, Alabama, 

 and it leaves no doubt in my mind as to their complete specific distinction." 

 Whitfield, 1886. 



Type Locality. Haddonfield, New Jersey. 



A single valve from the Matawan of Anne Arundel County has been 

 rather dubiously referred to this species because of the size and general 

 outline and the faint traces of a concentric sculpture. 



Occurrence. MATAWAN FORMATION. Ulmstead Point, Anne Arundel 

 County. 



