210 Systematic Paleontology 



however, that " we observe no necessary relation of the length of animals 



in proportion with the size of their teeth." 



The dimensions of the centrum are as follows : 



Length 69.0 mm. 



Depth of anterior face 49.0 mm. 



Depth of posterior face 60.0 mm. 



Width of anterior face 37.3 mm. 



Width of posterior face 49.5 mm. 



Depth of posterior concavity 9.5 mm. 



Least width of arch facet (ant.) 17.0 mm. 



Greatest width of arch facet (post.) 33.2 mm. 



The tooth of Priconodon comes nearest Leidy's Palceoscincus from the 

 Judith Eiver, to which it <30uld readily be ancestral, as the evolutionary 

 tendency on the part of the Orthopoda is to increase the number and 

 decrease the size of teeth. 



The vertebra is nearest to Stegos'aurus, but the equivalent vertebra 

 of Palceoscincus is unknown, and the association of vertebrae and teeth 

 is in each case conjectural. 



Occurrence. — Arundel Fq^RMATiON. Near Muirkirk, Contee, Prince 

 George's County. 



Collections. — U. S. National Museum, Goucher College. 



Order CROCODILIA 



Suborder EUSUCHIA 



Family GONIOPHOLIDAE 



Genus GONIOPHOLIS Owen 

 GONIOPHOLIS AFEINIS Sp. nOV. 



Plate XX, Fig. 7 

 Description. — A crocodile is represented by a number of teeth and 

 part of a scute. The teeth, however, are the most distinctive. They show 

 beyond question the generic characteristics of Goniopholis: "stout, 

 rounded, slightly curved, with the enamel ridged and grooved, and well- 

 marked carinas placed in a plane coincident with that of the curvature of 

 the crown." ^ They resemble very closely a multitude of teeth from 



^ Lydekker, British Mus. Catalogue Reptilia and Amphibia, pt. i, 1888, p. 79. 



