806 H. G. SEELEY ON NEW SPECIES OP 



might well be included under the Dicynodont type. The typical 

 forms of this group, such as Dicynodon testudiceps, have the anterior 

 nares almost as far forward as in the Theriodonts ; and there is a 

 sufficiently close resemblance between the lateral aspect of the 

 skull in Gorgonops and that of such a species as Dicynodon lacerti- 

 ceps to show that there is no character of importance, beyond the 

 single premaxillary bone in Dicynodon and the divided prem axillary 

 in Gorgonops, to place the genera in different groups. Nor is the 

 skull of Galesaurus so unlike that of the Dicynodon pardiceps in 

 form and position of the bony elements as to necessitate their loca- 

 tion in different orders. In fact the Theriodonts differ from the 

 Dicynodonts much as these differ from Oudenodonts. If the Therio- 

 donts are taken as the typical form, with all the teeth developed, 

 then the Dicynodonts are those genera in which the incisor and post- 

 carnassial teeth disappear ; and the Oudenodonts are the genera in 

 which all the teeth disappear, or are but slightly developed. A 

 fourth family may perhaps be indicated by Endothiodon, in which 

 the palate is covered with palatal teeth closely placed and irregu- 

 larly grouped. Professor Owen long ago characterized the first 

 three families just referred to under the excellent names Cynodontia, 

 Dicynodontia, and Cryptodontia, which he regarded as making up 

 the order Anomodontia*. I cannot find any evidence that the cha- 

 racters by which the Cynodontia differ from the other families are such 

 as would justify the institution of an ordinal group for them ; and 

 therefore urge that the name Theriodontia must rank as a synonym 

 of the family name Cynodontia. Procolophon can only be placed 

 among the Cynodontia on the hypothesis that it is a modification 

 of that typo in which the canine teeth have not become separable 

 from the others ; but I should prefer to regard it as belonging to a 

 parent typo from which the dental modifications of the Anomodontia 

 have been derived. And in that view there seem to me to be no 

 sufficient reasons for regarding the genus as other than an extinct 

 family of the Rhynchocephala. Professor Owen fully recognized the 

 affinity of the Dicynodonts in this direction when they were first 

 described ; and therefore this suggestion of affinities only raises 

 the question whether the Anomodontia and the South-African ani- 

 mals described as Dinosauria perhaps might not be united with the 

 Rhynchocephala into a subclass of Reptilia. Of the affinity of 

 Procolophon with the Anomodonts there can be no great doubt, 

 though there is no conclusive demonstration ; but, in common with 

 the Rhynchocephala, it has (1) a fixed vertical quadrate bone, which 

 (2) sends a process inward and forward to articulate with the 

 pterygoid, and (3) develops a strong process which extends outward 

 transversely to the main column of the bone and above the arti- 

 culation ; (4) both have teeth on the bones of the palate, though 

 apparently not on the same bones, and the pterygoid bones are 

 more closely united in the fossil than in the living type ; (5) in both 

 there are large, long, palatal vacuities beneath the anterior nares, 

 such as also occur in Lizards; (6) both types have the skull of 

 * See Owen's ' Paleontology,' 2nd ed. p. 258 t seq. 



