30 PALAEONTOLOGY OF NEW JEESEY. 



Ostrea crenulimarginata. 

 Plate III, Figs. 10 aud 11. 



Ostrea crenulimarginata Gabb. J. A. N. S., Phil., Vol. IV, 2d ser., p. 398, PL LXVIII, 

 Figs. 48 and 49. Sjmopsis, p. 152. Meek, Check-list, p. 6. 



Shell, as seen in a single upper valve, depressed convex and moder- 

 ■ ately smooth, of an irregular ovate outline, and marked by but few con- 

 centric lines of growth more prominent than striae. Faint indications of 

 radiating slria? show obscurely, but are more in the substance of tlie 

 shell than on the surface. On the interior the margin is finely crenulate 

 for two-thirds the length of the valve, being strongest near the hinge and 

 becoming fainter in the forward ])art. Muscular scar large, reniform, and 

 situated above the middle of tlie shell. 



I have seen but a single upper valve of tliis shell. It differs iu the 

 surface characters from Mr. Gabb's description of the species, but I judge 

 the characters given by him were partly from the lower valve, as he tigures 

 none other, and the upper Vcilve would naturally be much smoother than 

 the lower. In other characters it agrees very well. In general features 

 it does not differ very materially from specimens (casts) wliich I have 

 referred to 0. suhspatulata, L. & S., but the position of the muscular scar is 

 very much higher on the shell. 



Formation and locality. — From the lower marl bed, at Marlborough, 

 N. J., in the collection of the Rev. Dr. Schanck. 



Ostrea panda Mortou. 

 Ostrea panda Morton. Synopsis, p. 51, PI. Ill, Fig. 6, and PI. LXX, Fig. 10. 



This species, although described as a Cretaceous form by Dr. Morton, 

 and recognized as such in all the catalogues of Cretaceous fossils, has 

 proved to belong to the Eocene only; and so far as known to me has 

 not been found in the Cretaceous at any place. There are many specimens 

 of it in the collection of the Academy of Sciences at Philadelphia from the 

 Eocene of the Southern States, and among them the one figured on Plate 

 19, Fig. 10, of Morton's Synopsis. Examples of the casts, or rather impres- 

 sions in the marls of Plicatula iirticosa Morton, often closely resemble some 

 of the smaller forms of this oyster, and it is possible that Dr. Morton's speci- 

 men (Fig. on PI. 'd, Fig. (i) may have been such a one. 



