THE JURASSIC PERIOD. 251 



suited for walking. In particular, the femur, by its head pro- 

 jecting freely from the acetabulum, seems to claim a movement 

 of free stepping more parallel to the line of the body, and 

 more approaching to the vertical than the sprawling gait of 

 the crocodile. The large claws concur in this indication of 

 terrestrial habits. But, on the other hand, these characters 

 are not contrary to the belief that the animal may have been 

 amphibious ; and the great vertical height of the anterior part 

 of the tail seems to support this explanation, but it does not 

 go further. . . . We have therefore a marsh-loving or 

 river-side animal, dwelling amidst h'licine, cycadaceous, and 

 coniferous shrubs and trees full of insects and small mamma- 

 lia. What was its usual diet ? If- ex ungue leonem, surely ex 

 dente cibum. We have indeed but one tooth, and that small 

 and incomplete. It resembles more the tooth of Iguanodon 

 than that of any other reptile ; for this reason it seems pro- 

 bable that the animal was nourished by similar vegetable food 

 which abounded in the vicinity, and was not obliged to con- 

 tend with Megalosaurus for a scanty supply of more stimu- 

 lating diet." 



All the groups of Jurassic Reptiles which we have hitherto 

 been considering are wholly unrepresented at the present day, 

 and do not even pass upwards into the Tertiary period. It 

 may be mentioned, however, that the Oolitic deposits have 

 also yielded the remains of Reptiles belonging to three of the 

 existing orders of the class namely, the Lizards (Lacertilta), 

 the Turtles (Chelonia), and the Crocodiles (Crocodilia). The 

 Lizards occur both in the marine strata of the Middle Oolites 

 and also in the fresh-water beds of the Purbeck series ; and 

 they are of such a nature that their affinities with the typical 

 Lacertilians of the present day cannot be disputed. The 

 Chelonians, up to this point only known by the doubtful evi- 

 dence of footprints in the Permian and Triassic sandstones, are 

 here represented by unquestionable remains, indicating the ex- 

 istence of marine Turtles (the Chehne planiceps of the Portland 

 Stone). No remains of Serpents (Ophidians} have as yet been 

 detected in the Jurassic ; but strata of this age have yielded 

 the remains of numerous Crocodilians, which probably inhab- 

 ited the sea. The most important member of this group is 

 Teleosaurus, which attained a length of over thirty feet, and 

 is in some respects allied to the living Gavials of India. 



The great class of the Birds, as we have seen, is represented 

 in rocks earlier than the Oolites simply by the not absolutely 

 certain evidence of the three-toed footprints of the Connecti- 

 cut Trias. In the Lithographic Slate of Solenhofen (Middle 



