270 KANSAS UNIVERSITY SCIENCE BULLETIN. 



of bone instead of a bony ring to which the scutes are united. 

 The girdle as preserved is in the form of an arch and is com- 

 posed of three plates, only two of which are ridged. The under 

 surface is smooth and longitudinally convex. The part of the 

 girdle preserved measures 320 mm. in length and 110 mm. in 

 width. 



Stegopelta finds its nearest allies in Polacanthus, from the 

 Wealden of the Isle of Wight; in Paleoscincus, which must, I 

 think, include the Stereocephalus of Lambe, from the Belly 

 river deposits ; and Stegosaurus, from the Lower Cretaceous of 

 Wyoming and Colorado. The characters which separate Steg- 

 opelta from Stegosaurus and Paleoscincus have already been 

 considered. From Polacanthus the present form differs in the 

 whole surface of the ilium being covered in the former animal 

 with a firm mosaic of very small, somewhat rounded, plates, 

 which are scarcely at all sculptured, as I learn from Doctor 

 Williston, who has examined the type specimen. These plates 

 in Stegopelta are relatively quite large and strongly sculptured. 

 The present form differs from Polacanthus also in the diver- 

 gence of the points of the ilium anteriorly. In Polacanthus 

 the iliac region was entirely covered by a bony shield, but in 

 Stegopelta this shield was not continuous, but there was a space 

 between the anterior ends of the ilia which was filled, probably, 

 with small bony scutes. There have been many stegosaurian 

 dinosaurs described from various parts of the world, notably 

 North America and Europe. The group seems to have had a 

 very wide distribution geographically. 



In conclusion, I wish to express my gratitude to Dr. S. W. 

 Williston, not only for his kindness in turning over the material 

 to me for description but for his kindly interest and help during 

 the entire investigation. 



The specimen is in the Walker Museum, University of Chi- 

 cago. 



Since the above was written there have appeared two papers 

 describing two new types of dinosaurian reptiles closely allied 

 to the above-described form. One of these papers,* from the 

 American Museum of Natural History, is of especial interest, 

 since the material supplements in an excellent way that which 

 has just been described. Mr. Brown's restoration of the Ankij- 

 losaurus magniventris, while based in large part on Marsh's 



* Brown, Barnum, 1908. Bulletin Amer. Mus. of Nat. Hist., vol. XXIV, p. 187. 



