No. 2389. FAUNA OF THE MARYLAND ARUNDEL— GILMORE. 589 



After comparing the type and other teeth of Priconodon with the 

 teeth of Palaeoscincus and Stegosaurus in the National Museum col- 

 lections, I fully concur in Lull's conclusions as to their close resem- 

 blance to those of Palaeoscincus, but do not see that they are any 

 closer to the latter than to Stereocephalus tutus Lambe, 25 also an 

 Upper Cretaceous form from the Belly River of Alberta, Canada. 



In size, method of wear, and general characteristics the teeth of 

 Priconodon certainly indicate closer affinities with the armored dino- 

 saurs of the Upper Cretaceous than with Stegosaurus of the Morrison 

 formation. 



Although our classification of the American armored dinosauria is 

 somewhat in confusion at the present time, the discoveries of recent 

 years, much of the material as yet undescribed, shows that the 

 Upper Cretaceous forms belong to families distinct from the Morrison 

 Stegosauridae. Whether the Nodosauridae, Ankylosauridae, or 

 Scelidosauridae all represent valid families I am not prepared to say, 

 but it is to one of these, probably the Nodosauridae, that Priconodon 

 should be assigned rather than the tall plated Stegosauridae as 

 classified by Hay, 26 Lull, 27 and others. 



Order LORICATA 

 Family CROCODYLIDAE. 



GONIOPHOLIS? AFFINIS Lull. 



Plate 110, fig. 1. 



This crocodilian was founded on very scanty materials, the se- 

 lected type being the crown of a single tooth (Cat. No. 8452, U.S.N.M.) 

 (pi. 110, fig. 1), though other teeth and part of a dermal scute were 

 mentioned in the original description. 28 



Lull points out that while the teeth resemble, in size and shape, 

 those of crocodiles from the Morrison formation, yet they differ by 

 "having secondary ridges between the main ridges on the proximal 

 portion of the crown." The sculpturing of the scute is also shown 

 to be coarser than on any of those from the Morrison of the West. 



In view of the present state of our knowledge concerning the 

 extinct Crocodilia I do not believe it is possible to definitely deter- 

 mine the genus to which a form based on such meager materials 

 belongs, and until more diagnostic specimens are found it will un- 

 doubtedly remain a species of uncertain affinities. At this time it 

 has no apparent value for the correlation of this fauna and should 

 be eliminated from such consideration. Except for showing the 

 presence in the Arundel fauna of an extinct crocodilian these frag- 

 mentary specimens have but little significance. 



15 Contributions Canadian Paleontology, vol. 3, pi. 2, 1902, pp. 55-57. 



»s Bull. 179, U. S. Geol. Surv., 1902, p. 4%. 



" Rept. Md. Geol. Surv., 1911, Lower Cret., p. 207. 



» Idem, pp. 210-211, pi. 20, fig. 7. 



