236 EXTIXCT ORDERS OF REPTILES. 



limbs were very short, but the hind-limbs were long and like 

 those of Birds. The lyroxmial portion of the tarsus resembled 

 that of Birds in being anchylosed to the lower end of the 

 tibia ; but the didal portion of the tarsus — unlike that of 

 Birds — was free, and was not anchylosed with the meta- 

 tarsus. Huxley concludes that " it is impossible to look at 

 the conformation of this strange Eeptile, and to doubt that 

 it hopped or walked in an erect or semi-erect position, after 

 the manner of a bird, to which its long neck, slight head, and 

 small anterior limbs must have given it an extraordinary 

 resemblance." 



The last type of the Deinosauria which we shall notice 

 here is the singular genus Chondrosteosaurus (= Camaro- 

 saurus), comprising gigantic reptiles from the Cretaceous 

 formations of Britain and Nortli America, The size reached 

 by some of the species of this genus was enormous, the 

 length probably being sixty or seventy feet, while the mas- 

 sive construction of the skeleton is as remarkable as its mere 

 linear extension. Thus, in an American species, the first 

 cervical vertebra is " twenty inches in length and twelve in 

 transverse diameter, and one of the dorsals measures three 

 and a half feet in the spread of its diapophyses, two and a 

 half feet in elevation, with the centrum thirteen inches in 

 diameter " (Cope). The femur was six feet in length, and 

 the scapula five and a half feet ; while the neck was pro- 

 bably ten feet long. The vertebrae (fig. 579) are opistho- 

 ccelous, and the centra are hollowed out into large lateral 

 sinuses on each side, which are believed by Owen to have 

 been filled with unossified cartilage, but which Cope looks 

 upon as possibly having contained air. The trunk-ribs are 

 connected with the vertebrse by double articulation, as in 

 the Crocodiles. The neural arches of the vertebrae are im- 

 mensely elevated (fig. 579), and the sides of the centra are 

 excavated by depressions, which are conjectured by Owen to 

 have lodged saccular processes of the lung, and which Cope 

 believes to have communicated by open foramina with the 

 internal sinuses of the vertebral body. From the immense 

 size of the scapula and humerus, and the proportionately 

 small size of the pelvis, it may be safely inferred that these 



