

282 PALEONTOLOGY. 



dactyle ; the first shorter than the last, especially in the fore- 

 arm and hand ; both bearing to each other, and to the entire 

 body, nearly the proportions of those of the Monitor lizards, 

 but with the hind limbs proportionally longer, and the bones 

 of both limbs thicker and stronger. There are eight carpal, 

 and six tarsal bones. The digits of the hand present, from 

 the innermost outward, including the metacarpals 3, 4, 5, 6, 

 4, bones, respectively; the digits of the foot include 8, 4, 5, 

 6, 5, bones. 



Of existing reptiles, the large carnivorous Varanian moni- 

 tors (Varanus, Hydrosaurus, e.g.) offer most resemblance to 

 the Protorosaurus ; which had evidently the same powers of 

 progression, as well on land as in water. But this oldest 

 known lizard presented a more powerful and complex frame- 

 work. The neck is longer and stronger, the vertebrae rivalling 

 in proportion those of the Pterodactyles ; the head is rela- 

 tively larger, and with more firmly fixed teeth ; the dorsal 

 spines are loftier and larger than in modern monitors ; the 

 larger sacrum accords with the relatively larger and stronger 

 hind limbs. The more numerous diverging processes for the 

 attachment of the tail-muscles bespeak the more vigorous 

 actions of that part. All the vertebral bodies have sub-con- 

 cave articular ends ; and it may be concluded, from the length 

 and strength of the tail, from the peculiar provision for 

 muscular attachments in that part, and from the proportions 

 of the hind limbs, that the Protorosaurus was of aquatic habits, 

 and that the strength of its neck and head, and the sharp- 

 ness of its teeth, enabled it to seize and overcome the struggles 

 of the active fishes of the waters which deposited the old 

 Thuringian copper-slates. 



At Elgin, in Scotland, in a fine-grained whitish sandstone, 

 cemented by carbonate of lime, situated between " Old Bed" 

 and " Purbeck" formations, and resting conformably upon the 

 former, evidences of Saurian (Crocodilian and Lacertian) 



