268 KANSAS UNIVERSITY SCIENCE BULLETIN. 



cephalus which are almost identical with the scutes of Stego- 

 pelta. Hatcher (23) was certainly in error in criticizing Lambe's 

 association of these scutes with dinosaurian remains and in 

 claiming that they were of a crocodilian nature, since in the 

 present specimen there can be no doubt as to their dinosaurian 

 character. Nopsca (24) has also fallen into the same error 

 as did Hatcher when he says that crocodilian remains were 

 associated with the Polacanthus specimen. Seeley (25) has 

 described and figured scutes similar to the above in Crateomus. 

 Huxley (26) has described and figured identical scutes in Acan- 

 thopholis. Marsh (27) has figured some small bony scutes in 

 Triceratops. Owen has figured scutes of a like nature in 

 Scelidosaurus (20). Possibly other armored dinosaurs pos- 

 sessed such scutes. 



The question of the morphological value of these scutes is 

 an interesting one. Judging from the scutes in Stegopelta, one 

 would incline to the opinion that they represent the rudiments 

 of a complete bony armor which in time, had the dinosaurs 

 survived, might have covered the whole dorsum of Stegopelta' s 

 descendants. Such a suggestion might apply equally well to 

 our modern crocodiles. It is pretty certain that the scutes in 

 the crocodiles are not vestigial, since it is not now conceded 

 that the modern Crocodilia are descended from the ancient 

 armored teleosaurs (28). 



The dermal spines (plate LVI, fig. 1, plate LIX, fig. 3) are 

 all of a dense bony texture with the external surface pitted. 

 A portion of a small dermal spine is represented, natural size, 

 in plate LIX, fig. 3. Its base is broken away so it is impossible 

 to determine its extent, but this was, in all probability, not 

 considerable. One of the most peculiar portions of the dermal 

 armor is that represented in plate LVI, fig. 1, which is called 

 a large dermal spine, and which I have provisionally located 

 near the base of the tail. The spine is asymmetrical and is 

 lateral in position, having had a mate on the opposite side of 

 which nothing remains. 



The spine preserved is much broken and the distal tip is 

 lost. As reconstructed it is of massive proportions in com- 

 parison to the rest of the exoskeleton. In cross section it is 

 for the most part triangular, with two sides of the triangle 

 concave and one convex. It is rounded near the distal end. 

 The spine, unlike most elements of a similar nature, is bifid, 

 as is represented in the figure (plate LVI, fig. 1). The short 



