NO. ler.fi. OSTEOTAHIY OF CAMPTOSAURUS—GILMORE. 297 



1 . 



fied by external injury. On the posterior half, the comparatively 

 thin, plate-like part of the ilium is divided vertically, the two halves 

 swelling out to form the walls of a cavity which extends downward, 

 emerging on the ventral border. The cavity is longer than wide, 

 measuring on the upper border of the opening 8(5 nnn. in a longi- 

 tudinal direction and 46 mm. in the transverse, the ventral exit being 

 considerably smaller. As indicated by a deep depression on the dorsal 

 border, the injury was probably received from above. 



The exostosis of the bone was greatest on the front side of the 

 cavity where it measures 72 mm. in Avidth. The nornuil diameter of 

 this part of the ilium, as shown by one of the opposite side, is only 

 21 mm. A second injury was found on one of the caudal vertebrae 

 near the root of the tail, as indicated by the pathologic condition of 

 the spinous process, which is considerably enlarged and has near 

 its base an elongated opening w^hich perforates the bone. AMiile the 

 wound in the ilium must have been an exceedingly painful one at 

 the time of infliction, it in no way utterly disabled the animal, at 

 least to the extent of leading to its death, for, as shown by the speci- 

 mens, all of the broken margins of the bone had healed. Although 

 these injuries may have been inflicted by some of its large carnivorous 

 contemporaries, the position of the wounds suggests the idea that 

 this individual Avas a female who might have received the injuries 

 during copulation. 



The ischia of O. hroumi are comparatively slender, and while there 

 is a considerable expansion of their distal extremities, they lack 

 the massiveness of those of C dlspar. In the lightness of the struc- 

 ture of these elements, they apj^roach C. medius most nearly. 



The fore limbs and feet show no distinguishing characteristics. 

 The principal measurements of the vertebra^ and other parts will be 

 found in that part of the paper devoted to the osteology of Camp- 

 tosauriis. 



GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION. 



In North America, camptosaurian remains have been found in 

 southeastern Wyoming, in Albany and Carbon counties ; « Colorado, 

 near Canon City, and in the " Garden of the Gods", near Colorado 

 Springs; South Dakota, in Custer County, in the vicinity of Buffalo 

 Gap. Beyond the limits of the United States, specimens which have 

 been referred to C amptosaurus have been found in England, Isle of 

 Wight, and Hungary. 



All of the American species, with the possible exception of C. de- 

 2?ressiis, are from the Morrison beds (Atlantosaurus beds of Marsh), 



«Iu the Journal of Geology, XIII, No. 4, 1905, p. 348, Dr. S. W. Williston 

 reports the occurrence of Laomurus remains in Fremont County, near Lander, 

 Wyoming, in deposits considered lower Cretaceous in age. 



