South African Fossil Reptiles and Amphibia. 179 



From its general features this form seems to have affinities 

 with the Dromasauria, but it certainly differs from any of the 

 described forms. The most noticeable feature is the length of 

 the limbs, of which "the hinder are considerably longer than the 

 front legs. In Galechirus scholtzi the femur is only slightly longer 

 than the humerus ; in Galepns no measurements of the femur 

 have been given ; and in Galeops it is unknown. In all these 

 forms, moreover, the humerus is much longer than the radius 

 and ulna, while in the new form the upper arm is roughly the 

 same length as the lower arm. 



The presence of a distinct enlarged canine brings the form 

 nearer to the Therocephalia than to the Dromasauria. The 

 absence of intercentra in the dorsal region is a feature shared 

 with the Dromasauria and other Therapsida. The pectoral girdle, 

 as far as can be seen, shows no difference from those of the 

 Dromasauria. There is the same absence of a distinct acromion, 

 the same two large coracoidal elements. The humerus is of some- 

 what different form. The delto-pectoral crest extends further 

 down the shaft than in Galc^ns or Galeops. The absence of an 

 olecranon process to the ulna is paralleled in Galechirus. The 

 sacrum is not known in any of the hitherto-described Dromasauria. 

 The posterior process to the ilium is seen in Galepus. The structure 

 of the tarsus is also typically Dromasaurian as far as can be seen. 

 It must be noted, however, that some of the features such as 

 the presence of two coracoidal elements and the possible tarsal 

 structure in which this form parallels the known Dromasauria 

 are primitive features common to most of the South African 

 Therapsida. Indeed, the differences between the postcranial 

 skeleton of this form and that of the Therocephalia such as Icti- 

 dosuchus as far as the latter group is known are not very striking ; 

 and the nature of the dentition allies the form to the Therocephalia. 



The other long-limbed South African Permian reptiles are 

 Heleosaurus, Hcleophilns, Brooinia, and Mesosaurus. With none 

 of these is the form so closely allied as it is with the Dromasauria 

 and the Therocephalia, and it may be concluded that it is a Droma- 

 saurian specialised in the development of the limbs for swift 

 movement over the ground and akin to the Therocephalia in the 

 specialisation of the teeth. In the absence of a well-preserved 

 skull, however, it is impossible to dogmatise upon the systematic 

 position of the form. 



