390 On some new Reptiles from the Elgin Sandstone. [Dec. 15, 



narrow There is a large pineal fossa in the middle of a spindle- 

 shaped area, which area is formed by a pair of parietals posteriorly 

 and a single intercalary bone anteriorly. 



The palate is continuous with the base of the skull ; the pterygoids 

 on each side send off a distinct process to the quadrate region. 

 Towards the front 'the median part of the united pterygoids arches 

 upwards, and the outer sides descend, forming a deep groove; 

 from the evidence of other specimens it is clear that the palatines, 

 extending inwards, converted this groove into a tube, and thus formed 

 the posterior nares. The ramus of the lower jaw is deep, with a 

 large lateral vacuity, and the two rami are completely united at the 

 symphysis. The back of this skull is not seen, but two other spe- 

 cimens", referable to this same genus, show that the occiput had two 

 post-temporal fossas on each side. 



This specimen is distinguished from Dicynodon by the presence of 

 two post-temporal fossa? 011 each side of the occiput, by the small size 

 of the maxillary tusk ; and probably by the elongated spindle-shaped 

 area enclosing the pineal fossa, and also by the slight ossification of 

 tho vertebral centra. 



A second and much smaller specimen, provisionally referred to 

 Traquairi, has, besides the skull, a fore-limb well preserved. The 

 humerus of this shows the usual Anomodont expansion of its extremi- 

 ties ; its large deltoid crest is angular, and set obliquely to the distal 

 end. 



Three other species are referred to the same genus, namely : 



Gordonia Huxleyana, which is distinguished from G. Traquairi by 

 its proportionately wider and more depressed skull, and by the absence 

 of the concavity between the orbits which is present in the latter 

 species. The humerus has the distal extremity oblique to the deltoid 

 crest, which was probably rounded and not angular. 



G. Duffiana has the skull even wider than in G. Huxley ana, and the 

 portion of a humerus found with this skeleton has the two extremi- 

 ties set nearly at right angles to each other. 



G. Juddiana has an elongated skull resembling that of G. Traquairi^ 

 but the parietal crests are less developed, the bones of the nasal 

 region are much thickened and overlap the nasal apertures, the small 

 tusk is placed a little further back and points more directly down- 

 wards, and the pineal fossa is smaller than in either of the other 

 species. 



A second generic form is named Geikia Elginensis. This is a skull 

 nearly allied to Ptychognathus, Owen, but is .distinguished by its 

 shorter muzzle and the entire absence of teeth; the upper part of the 

 skull, between the orbits, is also peculiar, forming a deep valley open 

 anteriorly, with a ridge on each side, the anterior end of which forms 

 a lar^e prominence above and in front of the orbit. The occiput has 



