14 



REVISION OF THE PELYCOSAURIA. 



In the same year the translation of Zittel's Grundziige der Paleonto- 

 logie (136) presented the following classification: 



Order Rhynchocephalia. 



Suborders Proterosauria, Pelycosauria, Rhyyichocephalia vera. 



In the same year von Huene (102) described a form, Ctenosanriis^ from 

 the Triassic, which he places in his list next to the Theriodontia, but gives 

 only the family Clepsydropida: to indicate its position. 



In the same year Osbom & McGregor presented their paper on the 

 divisions of the Reptilia (112). All the reptiles were divided into sub- 

 classes, the Diapsida and Synapsida. The Pelycosauria are placed with the 

 Mcsosauria, Proganosauria, etc., in the order Rhynchoceplialia of the Diap- 

 sida. 



In the next year, 1903, appeared Osbom's Memoir on the same subject 

 (113), in which the classification is elaborated as below with some minor 

 changes from the original paper. 



Subclass Synapsida. 

 Primarily with single or undivided temporal arches. 

 I. Cotylosauria. 

 II. Anomodoniia (Superorder) . 



1 . Theriodon tia . 

 Cynodontia. 

 Gomphodontia. 



2. Dicynodontia. 



3. Placodontia. 



III. Testudinata. 



IV. Sauropterygia. 



1. Noihosaiiria. 



2. Plesiosauria. 



Giving rise to the Mammals through some unknown 

 ancestor of Anomodonts. 



Subclass Diapsida. 



Primarily with double or divided temporal arches. 



I. Diaptosauria (Superorder). 



1 . Proterosauria . 



2. Pelycosauria. 



3. Rhynchosauria. 



4. Procolophonia. 



5. Proganosajiria. 



6. Choristodera. 



7. Rhynchocephalia. 



II. Phyiosauria (including the Belodonts 

 and A'eiosaicrs). 



III. Ickthyosauria. 



IV. Crocodilia. 



V. Dinosauria (Superorder). 



1. Theropoda. 



2. Cetiosauria. 



3 . Orthopoda . 



VI. Squamata (Superorder). 



1. Laceriilia. 



2. Mosasauria. 



3. Ophidia. 

 VII. Pterosauria. 



Giving rise to the Birds through some unknown type 

 transitional between Proterosauria and Dino- 

 sauria. 



