52 PALEONTOLOGY OF NEW JERSEY. 



marked, not so straight, and extend down the valve not so far as on the 

 opposite valve. Snrface of the valves smooth and shining to the naked eye, 

 but under a lens is seen to be marked by fine concentric lines of growth, 

 and on the left valve by faint, incipient, radiating lines. 



The above description is taken from specimens from Eufaula, Ala., 

 the locality fi'om which the species was originally described. The valves 

 present every appearance of having been gaping on the sides when perfect, 

 being bent even as seen on the soft marls when preserved only as separated 

 shells; consequently the species would properly be classed as an Amusium 

 and not as Pseudamusimn or Sincyclonema, both of which genera are subdi- 

 visions only of the other, and differ but very slightly. There is no other 

 form known from the American Cretaceous strata sufficiently resembling it 

 to be easily mistaken for it. Sincyclonema rigida H. & M. sp. is the nearest, 

 but it is much more elevated in proportion to its width, being ovate in out- 

 line. The ears are smaller, the hinge-line straight instead of depressed in 

 the middle, and the valves are more strongly marked both by concentric 

 lines and radii 



Formation atid locality. — The only specimens which I have observed 

 from New Jersey were from Monmouth County, New Jersey, and are too 

 imperfect for illustration. The specimens illustrated are from Eufaula, Ala. 



Amusium Couradi, ii. sp. 

 Plate VII, Figs. 8-10. 



Syncyclonenia ? simplicia, Courad. Am. Jour. Concli., Vol. V, p. 99, PI. IX, Fig. 20. 



Not of Meek, Check-list, p. 7. 

 Not Pecten simplkms, Con. J. A. N. S., PLil., 2(1 ser.. Vol. IV, p. 283, PI. XVI, Fig. 



44, or Gabb, Synop., p. 160. 

 Not Pseudamusimn simplica. Stoliczka. Pal. Indica, Vol. Ill, p. 420. 

 Pecten simpUcus (Con.) Meek. Geol. Snrv. N. J., 1868, p. 725. 



Shell small, seldom exceeding half an inch in height; erect-ovate, be- 

 coming more elongate proportionally with increased growth. Valves slightly 

 convex. Hinge shoi't, from half to two-thirds as long as the width of the 

 body of the shell, strongly and distinctly auriculated. 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. 



