1 86 WATER REPTILES OF THE PAST AND PRESENT 



African reptiles from the Lower Trias had certain very definite 

 characters entitling them to an independent position, for which he 

 proposed the order Pelycosimia. Upon the whole, however, these 

 characters seem to be primitive parasuchian, and the group may 

 provisionally be placed in the order Parasuchia, as a third suborder, 

 the Pelycosimia. The order Parasuchia, then, until we know much 

 more about the latter two groups, may be conveniently divided 

 into three suborders, the Phytosauria, Aetosauria or Pseudosuchia, 

 and the Pelycosimia, all of Triassic age. 



McGregor was quite right in retaining for the suborder the 

 name Phytosauria, suggested by Jaeger in 1828, inappropriate as 

 the word is etymologically, but was hardly justified in substituting 

 the generic name Phytosaurus for the long and well-known Belodon, 

 because it is quite impossible to say that Jaeger's very fragmentary 

 specimen upon which he based the genus Phytosaurus really is the 

 same as Belodon. Professor Fraas very kindly showed the writer 

 the original type-specimen of Jaeger, now preserved in the Stutt- 

 gart Museum, and both are agreed that it is impossible to prove 

 the identity of Belodon and Phytosaurus from the very fragmentary 

 and imperfect specimen. It is quite as probable, for instance, that 

 Phytosaurus and Mystriosuchus are identical as that Phytosaurus 

 and Belodon are. Unfortunately, this is not the only case in ver- 

 tebrate paleontology where the fragmentary specimens to which 

 names have been given are inadequate to determine the species, 

 or genus, or even the family to which they belong; there have 

 been very many such instances. The pioneers in paleontology 

 were often justified in naming small and obscure fragments of 

 bones, or single bones. One would be justified even yet in giving 

 a name to an indeterminable fragment of a bird bone from the 

 Triassic formation, because the discovery of a bird of any kind in 

 that formation would be very important for science, even if its 

 precise kind might never be recognized from the specimen. 

 Nevertheless, the custom is a very reprehensible one when indis- 

 criminately followed. For these reasons the writer disagrees with 

 McGregor in substituting the inappropriate name Phytosaurus for 

 Belodon, the name by which the most typical forms were so long 

 known. 



