.84 Notices of Memoirs — Classification of the Dinosaiiria. 



Sub-Order Ccelttria (Hollow tail). 



(5) Family Coeluridce. Bones of skeleton pneumatic or liollow. 

 Anterior cervical vertebrae opisthocoelian, remainder biconcave. 

 Metatarsals very long and slender. 



Genus Codurus. 



Sub-Order Compsognatha. 



(6) Family Compsognathidce. — Anterior vertebrae opisthocoelian. 

 Three functional digits in manus and pes. Ischia with long sym- 

 physis on median line. Only known specimen European. 



Genus Compsognathus. 



DINOSAURIA ? 

 (5.) Order Hallopoda (Leaping foot). Carnivorous ? 



Feet digitigrade, unguiculate ; three digits in pes ; metatarsals 

 greatly elongated ; oalcaneum much produced backward. Fore 

 limbs very small. Vertebree and limb bones hollow. Vertebrae 

 biconcave. 



Family HallopodidcB. 



Genus Hdllopus. 



The five orders defined above, which I had previously established 

 for the reception of the American Jurassic Dinosaurs, appear to be 

 all natural groups, well marked in general from each other. The 

 European Dinosaurs from deposits of corresponding age fall readily 

 into the same divisions, and, in some cases, admirably supplement 

 the series indicated by the American forms. The more important 

 remains from other formations in this country and in Europe, so far 

 as their characters have been made out, may likewise be referred 

 with tolerable certainty to the same orders. 



The three orders of Herbivorous Dinosaurs, although widely 

 different in their typical forms, show, as might be expected, indica- 

 tions of approximation in some of their aberrant genera. The 

 Sauropoda, for example, with Atlantosaurus and Brontosaurus, of 

 gigantic size, for their most characteristic members, have in Moro- 

 saurus a branch leading toward the Stegosauria. The latter order, 

 likewise, although its type genus is in many respects the most 

 strongly marked division of the Dinosaurs, has in Scelidosaurus a 

 form with some features pointing strongly towards the Ornithopoda. 



The Carnivorous Dinosauria now best known may all be placed 

 at present in a single order, and this is widely separated from those 

 that include the herbivorous forms. The two sub-orders defined 

 include very aberrant forms, which show many points of resemblance 

 to Mesozoic Birds. Among the more fragmentary remains belong- 

 ing to this order, but not included in the present classification, this 

 resemblance appears to be carried much farther. 



The order Hallopoda, which I have here referred to the Dinosauria, 

 with doubt, differs from all the known members of that group in 

 having the hind feet especially adapted for leaping, the metatarsals 

 being half as long as the tibia, and the calcaneum produced far back- 

 ward. This difference in the tarsus, however, is not greater than 



