256 D. M. 8. Watson — Lhnbs of Lystrosaurus. 



V, — The Limbs ok Zystbosadsus. 



By D. M. S. Watson, M.Sc, Lecturer in Vertebrate Palaeontology, University 

 College, London. 



T YSTROSAURUS, Cope — PtycJiognathus, Owen {non Stimpson), 

 has long been known from isolated but often perfectly preserved 

 skulls. Quite recently the reception of a magnificent skeleton by the 

 Albany Museum, Grahamstown, enabled me to give a restoration of 

 the animal. In this drawing the hand and foot were drawn from 

 incomplete non-associated remains. Whilst travelling in South Africa, 

 with the aid of a grant from the Percy Sladen Trustees, I collected 

 on the farm Ivlip-kuil a fragmentary skeleton of Lystrosaurus, much 

 of which was so rotten that it could not be preserved, but which 

 included a complete left fore-limb. This was developed by myself 

 and was found to lie in its natural position with the digits very 



Fig. 1. Left forearm of Lystrosaurus sp., Klip-kuil, District Albert, Cape 

 Colony. Viewed from the front. X ^. The lower end of the humerus is 

 broken so as to show the articular face of the upper end of the radius. 



strongly flexed, except that the metacarpals were slightly separated 

 laterally. It is represented in Text-tig. 1, with the humerus, 

 radius, and ulna in the position in which they were found, and with 

 the fingers extended. The humerus is not very well preserved, 

 but agrees exactly with the excellent example figured by Owen, 

 Catalogue of South African Fossil Reptiles. It is of the usual 

 Anomodont type, with a very powerful deltoid crest ex;tending half- 

 way down the shaft, and a much expanded lower end with a large 

 entepicondyle. There is a large eutepicondylar foramen, but no 



