583 



February 20, 1862. 



Major-General SABINE, President, in the Chair. 

 The following communication was read : 



"On the Dicynodont Reptilia, with a Description of some 

 Fossil Remains brought by H.R.H. Prince Alfred from 

 South Africa in November I860." By Professor R. OWEN, 

 F.R.S. &c. Received January 23, 1862. 

 (Abstract.) 



In this paper the author describes some fossil remains obtained, 

 at the suggestion of H.R.H. the late Prince Consort, by H.R.H. 

 Prince Alfred, during his journey in South Africa. They are refer- 

 able to two genera of Dicynodont Reptilia. The first specimen is an 

 unusually perfect specimen of the skull, retaining the lower jaw in 

 connexion with the tympanic pedicles, of a species of Ptychognathus, 

 showing distinctive characters from previously described species, 

 and which the author dedicates to its discoverer under the name of 

 Ptychognathus Alfredi. The anatomical characters of this fossil 

 were described in detail. It was obtained from a greenish sandstone, 

 probably Triassic, of the Rhenosterberg, South Africa. 



The second specimen is the skull, with the lower jaw, also in situ, 

 of a true Dicynodon, referable by its size to the largest known spe- 

 cies (Dicynodon tigriceps, Ow.). The right maxillary and zygo- 

 matic arch having been partially removed in quarrying the rock 

 containing the fossil, a further detachment of the matrix brought 

 into view the descending cranial plate of the frontal, the inter- 

 orbital septum, the upper surface of part of the bony palate with 

 the pterygoid, and the rhinencephalic continuation of the cranial 

 cavity. The presphenoid projects forward as a compressed plate, 

 exceeding in relative length and extent of ossification that in Che- 

 Ionia, and more resembling that in Crocodilia. Anterior to the pre- 

 sphenoid is the vomer, which expands laterally to join the palatines 

 and pterygoids. Other cranial characters deducible from the pre- 

 sent and not shown in previous specimens are noticed. As a whole, 

 the skull exemplifies the near equality in size of this extinct two- 

 tusked reptile of South Africa with the existing Walrus ; and it 



