108 BARON F. NOPCSA ON THE PRIMITIVE REPTILIA [vol. lxxix, 



convenient appellation 'sporadic,' but with the survival of a 

 primitive fauna. At this point, it becomes obvious why it was 

 important to fix the age of this fauna beyond all doubt. 



In recent times a situation similar to that established for. 

 Transylvania in the Cretaceous Period is only to be met with in 

 Australia, where the diluvial and prehistoric fauna likewise con- 

 sisted exclusively of elements that had long vanished in other 

 parts of the globe. 



Having established this fact, we must try to find the reason. 

 Practically the same fauna as in the latest Cretaceous of Transylvania 

 is met with in the Garvimnian of Southern France, where, among 

 others, Rhahdodon priscum occurs, as well as a IIierosaurus-]ike 

 plated Dinosaur (18) which evidently is closely allied to StrutJiio- 

 saurus, the same crocodile as in Transylvania. But the tortoises 

 are different, the French Polysternum (67) probably being merely 

 a pathologically deformed member of the Amphichelydse. The 

 French Sauropod Hypselosaurus (50) seems to be closely allied 

 to Titanosaurus, although generically distinct, and Titanosaurus 

 itself occurs at St. Chinian (17). From the Maestrichtian strata 

 in Belgium are known the Dinosaurs Orthomerus (19, 72) and a 

 form allied to Iguanodon, called Craspedodon (19), as well as a 

 Theropodous Dinosaur of uncertain systematic position denomi- 

 nated ' Megalosaurus'' bredai (72). The crocodile Thoracosaurus 

 (38) differs from the Danian type. Other land-animals are not 

 known in the Maestrichtian. 



From the Turonian strata of Lower Austria come Rhabdodon 

 (73) represented only by fragments of an immature male ; Struthio- 

 saurus, male and female ; and a short-snouted crocodile Rhadino- 

 saurus (13), traces of which have been found in Transylvania and 

 France. The tortoises are too badly preserved to permit identi- 

 fication ; the Pterosaurian seems to belong to the Ornithoeheiridse, 

 but this is not quite certain. Going back from the Turonian to 

 the Cambridge Greensand, we find numerous Ornithocheiridse, a 

 Rhabdodon-like animal (Anoplosaurus) , then a Trachodont Dino- 

 saur related probably to the Protrachodontidre (48). Moreover, 

 there occurs a species, of Acanthopholls (71, 54) and a large 

 Sauropodous Dinosaur, Macrtirosaurus (71). 1 Crocodiles of un- 

 certain systematic position [Crocodilus proavus Seeley, etc. 

 (69, 70)] occur likewise. 



The farther we go back in the chronology, the more types are to 

 be met with differing from the Transjdvanian fauna. Even if we 

 admit that the differences are to a certain extent due to zoo-geo- 

 graphical distribution, this does not explain every circumstance, 

 Rhabdodon and Orthomerus having co-existed in England with 

 Macrurosaurus, and in Belgium with Craspedodon. Therefore 

 the Transylvanian fauna, well known in consequence of the vast 

 amount of collecting that has been in progress for twenty-five 



1 A revision of the Dinosaurs of the Cambridge Greensand will be pub- 

 lished elsewhere. 



