REPTILIA : SEYMOURIA 63 



mated from the accurately measured taper of the six proximal 

 vertebrae, and upon the whole, I think it is too long. However, 

 it is possible that the distal vertebrae may have been elongated, 

 and the tail even longer than is shown. At the first opportunity 

 search will be made in the locality where the specimen was found 

 for the missing part, and I doubt not that the search will be 

 successful. 



Relationships. — From the above description and figures it is 

 evident, I think, that the relationships of Seymouria are not very 

 intimate with any other reptiles known from the Permian; at 

 least any that are tolerably well known. In the skull the presence 

 of the deep otic notch, the arrangement and number of the temporal 

 bones, the slender, elongate teeth, longest in the maxillae, and the 

 shape, all differentiate the genus widely from either Diadectes or 

 Limnoscelis, as well as the chief forms now referred to the Parioti- 

 chidae, and also from the known foreign forms. The speculation 

 again recurs as to whether or not the temporal vacuity of the higher 

 reptiles may not have arisen by the prolongation of the tabular 

 angle to meet the quadrate and the consequent inclusion of the 

 ear-notch. Precisely this did occur in some of the contemporary 

 temnospondyls. Against the probability of this is the fact that 

 the quadrate must have changed somewhat its relations with the 

 contiguous bones; although as a matter of fact we do not know 

 what the relations of the quadrate were in any temnospondyl. I 

 do not think that this would be impossible, since I cannot under- 

 stand the condition in Cacops and Dissorophus, unless the flat 

 process bordering the posterior bar in front is really the quadrate. 

 However, speculations on this subject are premature. Among the 

 Cacops material that has been recovered since my description of 

 the genus was published are not less than eight good skulls, and 

 there are doubtless as many more yet to be recovered. It will be 

 strange if, from among all this material, the detailed structure of the 

 skull is not finally determined. The transfer of the ear-cavity 

 from the inclosed opening in Cacops to a place back of the vacuity is, 

 however, quite another matter. 



In any event it is certainly very remarkable that this cotylosaur 

 reptile with all its other strange amphibian affinities should mimic 



