256 DESCRIPTION OF VERTEBRATE REMAINS, CHIEFLY ^ 



The marginal dental armature is composed of a number of horizontal rows of 

 small curved quadrate plates associated by intervening ossific substance. The 

 anterior face of the armature resembles that of a wall built of tiles imbedded in 

 mortar. 



The oral dental armature is made up on each side of about ten plates united 

 by cementum. The unworn plates, as seen on the surface of the piles opposite 

 the triturating surface, are variable in outline in different specimens, as represented 

 in figures 15& and 18. The differences might be suspected to be specific, but in 

 eight specimens no two are alike. 



The age of the fossils, like many others of the Asliley phosphate beds, is 

 uncertain. They are supposed to be derived from the so-called eocene marl rock. 



Professor Cope has indicated specimens from the raiocene of North Carolina 

 (Kerr's Eeport of the Geol. Surv. of N. C, 1875, Appendix, p. 31, PI. viii., fig. 6), 

 which he attributes to the same species, but inadvertently ascribes them to me 

 under the name of Diodon antiquus. 



PHARTNGODOPILUS. 

 Specimens of pharyngeal bones thickly crowded with molar teeth, found in 

 miocene and pliocene formations of Europe and Africa, have been referred by 

 Prof. Igino Cocchi of Florence, to an extinct genus of labroid fishes under the 

 above name. (Monografia dei PharyngodopilidEe, Firenze, 1864.) 



Pharyngodopilus carolinensis. 

 Odax carolinensis, Jjeidy : Proceedings Academy Natural Sciences, 1855, 396. 



Specimens of isolated pharyngeals thickly crowded with teeth, resembling 

 those referred to the above genus, are occasionally discovered in the Ashley phos- 

 phate beds of South Carolina. Specimens of the kind, together with others of 

 maxillaries and teeth, obtained by the late Capt. Bowman from the sands of Ashley 

 River, were described by me in the Proceedings of this Academy in 1855, under 

 the name of Odaj^- carolinensis. 



Figure 19, Plate xxxiv., represents an inferior pharyngeal, so closely crowded 

 with teeth that scarcely a vestige of the bone in which they are imbedded is 

 visible. The largest teeth are central and posterior. The original form of the 

 teeth as seen on the masticating surface, would appear to have been hemispherical, 

 but in many cases, from their crowded condition, they have assumed a more or less 

 irreo'ular form. The surface of the pharyngeal bone opposite to the masticating 

 pavement of teeth is crowded with fewer and larger empty cavities of reserve for 

 teeth. 



