70 THIRD GENERAL MEETING. 



the skull like the supra-temporal which are not known in the higher 

 reptilia. 



Some Dinosaurs like Belodon are near to Anomodonts. 



The animal types which are included in this extinct group 

 comprise the heavy Pareiasauria, the Dicynodontia, the more 

 slender Theriodontia, the Mesosauria and others represented by 

 Endothiodon and Procolophon. In common with their North 

 American allies these Permian reptiles agree in having the head of 

 the rib articulated between the bodies of two vertebrae in a manner 

 which is typically mammalian. The nearest approach to this 

 condition among reptiles is seen among Chelonians. 



The shoulder girdle in Pareiasaurus and Dicynodon may be 

 closely compared with the same bones in Monotreme mammals, 

 although they are blended together in most of the specimens by 

 sutures. The clavicular arch in Pareiasaurus and Kisticephalus 

 appears to include a pair of epiclavicular bones which are only found 

 in Labyrinthodont reptiles. These epiclavicles are unknown in 

 reptiles and mammals. 



The pelvis is usually comparable to that of a mammal though 

 no one Anomodont parallels all the conditions in any mammal. 

 In the hind limb the femur in Procolophon is a type between 

 Testudo and Ornithorhynchus ; in Dicynodonts the bone is 

 Edentate. In some Theriodonts the femur is not typically mam- 

 malian and is more like some Dinosaurs. 



There is a similar diversity of character in the fore-limb, 

 Theriodesmus shows a humerus more Marsupial, while Microgom- 

 phodon is more like a Monotreme. 



The skull in many Theriodonts is typically mammalian in form, 

 but the lower jaw is always formed of many bones ; and the dentary 

 bone never quite reaches the articulation for the lower jaw. This 

 makes an interval of structure between Anomodonts and Mammals. 



The teeth show some new types, such as Ptychocynodon, but the 

 molars may mostly be compared with carnivora in Cynognathus, 

 rodents, insectivora in Diademodon and Trirachodon, and there are 

 other mammalian types. The mammalian characters of the teeth 

 may be compared with the mammalian characters of the skeleton. 



Anomodonts are not the parents of mammals, but a collateral 

 and closely related group. The common parent of both may be 

 sought in rocks older than Permian, perhaps in Silurian or 

 Devonian strata. The remains thus far discovered in Permian 

 rocks show so near an approach of the higher reptiles to the lower 

 mammals, that it is reasonable to believe that the interval between 

 them is now so small that it may be obliterated by future dis- 

 coveries. There is however thus far no evidence that the mammalian 

 type of brain had come into existence in these animals. 



Professor OSBORN^ of New York, said that certain general 



^ For a full report of Professor Osborn's remarks, see Appendix. 



