22 F. von Huene — Order Thecodontia. 



Akt. II. — The Triassic Reptilian Order Thecodontia; by 

 F. von Huene. 



During- the last several years the writer has been much 

 occupied with reptiles of the order Thecodontia (see Nos. 

 10-20 of the literature list at the end of this paper) and 

 allied groups. In the present paper I am going to give 

 briefly the results as regards classification and relation- 

 ship. The latest literature is given at the end, and all 

 other papers will be found quoted in these. 



The order Thecodontia (E. Owen 1859) consists of 

 three suborders: Pseudosuchia (Zittel 1889), Parasuchia 

 (Huxley 1875) and Pelycosimia (Huene 1911). The 

 animals constituting these three suborders are of very 

 dissimilar form and size, but are anatomically very nearly 

 related. The Pseudosuchia form the radicle stock of the 

 whole group. Both of the other suborders spring from 

 early Pseudosuchians, but have no descendants them- 

 selves; the Pseudosuchians give rise probably to all 

 Archosauria. 



The Pseudosuchia I propose to classify as follows : 



(Proterosuchus fergusi 



Proterosuchidse . . . \Dyoplax arenaceus 



[Erpetosuchus granti 



Sphenosuchida? Sphenosachus acutus 



Ornithosuchus woodwardi 

 Omithosuchus taylori 

 Saltoposuchus connectens 

 Saltoposuchus longipes 

 Pedeticossaurus leviseuri 

 ScleromochlidEe Scleromochlus taylori 



Euparkeriidse . . S Eu P ar ^ er i a capensis 



' VBrowniella afficana 



Aetosauridffi Uetosaurus ferratus 



(Aetosaurus crassicauda 

 Stegomosuchidse Stegomosuchus longipes 



Ornithosuchidae 



With regard to the last of these forms, it was first 

 described as Stegomus longipes by Emerson and Loomis. 6 

 Then the writer re-investigated it at Amherst in 1911 and 

 published his results in 1914. 13 The skull now agreed 

 with some of the other Pseudosuchians, but extremities 

 and dermal plates were different. It has a long skull and 

 less than half of its length is preserved. This form can- 



