212 Prof. R. Owen on the Occurrence 



expanded at their termination, " and thus touch each other, 

 or nearly so, at their ends " *. 



A large foramen so enclosed is shown in the figure cited. 

 This characteristic of the Dinosaurian sacrum is more stri- 

 kingly exhibited in the 5-jointed one of thelguanodon, in which 

 there are four such large foramina on each sidef. 



We have thus ground for testing the inference drawn by 

 Prof. Cope, viz. that, with regard to the bulky Saurian of 

 Dakota, " the weight was not borne on the hind limbs." This 

 statement has a meaning on the assumption that the Professor 

 accepts the notion that the previously known Dinosauria, or 

 some of them, marched on their hind legs like birds. What 

 proportion of the weight of Chondrosteosaurus might be so 

 sustained we may infer from the analogy of Scelidosaurus. 

 Of this Dinosaur both humerus and femur of the same indi- 

 vidual are preserved in the specimen now in the British Mu- 

 seum. The relative size of these bones affords an estimate of 

 the share they respectively took in the sustentation and motion 

 of the Saurian on dry land. The femur \ is twice the length 

 and more than twice the thickness, in the shaft, of the hume- 

 rus§. 



It may be that well-ascertained specimens of these bones 

 in Chondrosteosaurus will exhibit similar proportions. 



Prof. Cope, however, writes, '' The bones of the tail and 

 limbs are solid or nearly so, in great contrast with some of the 

 Dinosauria of later geological periods. Another peculiarity, 

 of the genus Camarosaurus at least, is the probable great 

 length of the anterior limbs. The scapula is enormous as 

 compared to the pelvic bones " ||. " The great length of the 

 humerus in the probably allied genus Bystrofiheus^ from the 

 trias of Utah, adds to the probability that the same bones 

 were large in Camarosaurus. This character, taken in con- 

 nexion with the remarkably long neck possessed by that genus, 

 suggests a resemblance in form and habits between these huge 

 reptiles and the giraffe"^. 



Until, however, a humerus of Chondrosteosaurus be unequi- 

 vocally discovered, it appears to me that the analogy of the 

 dinosaurian Scelidosaurus offers safer guidance than the mam- 

 malian genus Camelopardalis. 



• "Monograph on a Fossil Dinosaur," &c., in the Palaeontological 

 Society's volume issued 1862, p. 7, pi. vi. fig. 1. 

 t Owen, ' History of British Fossil Reptiles,' 4to, pt. vi. (1855) pi. 8. 

 i Monogr. 1855, pi. x. 65. 

 § Ibid. pi. iii. 53. 



II Proc. Amer. Philos. Soc. 1877, p. 233. 

 f Ibid. p. 234. 



