Cope.] 312 [February 17, 



finely striate, the stride coarser at the point of convergence at the 

 orifice of the pulp cavity. 



The crown in many of the teeth has been broken away, leaving the 

 short conic pulp cavity and its thin walls exposed. - 



The bone itself is convex in transverse direction, descending more 

 gradually on the convex margin. 



Lines. 



Length of bone 19.5 



Width " 10 



Thickness of bone 3.2 



This interesting species left its remains in the JNIiocene marl near 

 Shiloh, Cumberland Co., N. J. 



ELASMOBRANCHI. 



Pristis amblodon Cope. 



This name is proposed for a species whose remains occur in the 

 Eocene Green-sand bed of New Jersey. It is characterized by the 

 peculiarity that both its edges are similarly obtusely rounded, instead 

 of the posterior being grooved, as usual in the genus. Associated 

 with this arrangement both edges are curved to the tip, and not one 

 only, as usually, though one curvature is greater than the other. The 

 form of the teeth is neither slender nor stout, and they are not 

 curved out of the horizontal plane. Surface smooth. Length six- 

 teen lines; width at basis five lines. 



Pristis brachyodon Cope. 



Founded on some teeth from the Green-sand of Petersburg, Vir- 

 ginia. Width at base two and four fifths times its length ; anterior 

 edge heavily rounded, oblique, posterior straight, flat, with a shallow 

 and narrow sulcus on the basal two fifths. For about the same ex- 

 tent on one side about ten longitudinal ridges at irregular distances. 

 Without vertical curvature; tip not attenuated, general proportions 

 heavy. 



The teeth from different parts of the premaxillary weapon of the 

 Pristes agree very closely in structure, and any of them indicate the 

 species with equal accuracy. Of extinct Piistes, three are named 

 and one described in the Poissons Fossiles of Agassiz, Galeotti has 

 described P. Lathami, and Prof. Leidy has made known two from the 

 United States, P. ensidens from the Pliocene of Ashley lllver, and 

 the gigantic P. curvidens from the New Jersey Green-sand. 



The teeth of the former are acute on both edges, and are broader 



