RECORDS 111 



Summary of Papers. 



Professor Osborn stated that the only fossil Primates at pres- 

 ent known are those in the Eocene. The supposed Oligocene 

 genera described by Marsh and Cope have proved to belong to 

 the Artiodactyla. Associated throughout with the discovery and 

 literature of the primates is the family Mixodectidae, including 

 MixodectiS of the basal Eocene or Torrejon beds ; Mathew has 

 suggested that this animal is a rodent. Careful comparison of 

 this type with the supposed primates Cynodontomys of the Mid- 

 dle Eocene and Microcyops of the Upper Eocene proves that 

 these animals also belong probably with the Rodentia ; they 

 represent a primitive stock with strong affinities to the Tillo- 

 dontia which are thus brought nearer to the ancestral rodents. 

 This conclusion removes all these animals from the primates 

 where they have hitherto been placed. This leaves three fami- 

 lies of monkeys as follows : Hypsodontidae including Hypsodus 

 and Sarcolemur, animals of medium size retaining the typical 

 series of 44 teeth ; a second family, the Notharctidae, including 

 Pelycodus and NotJiarctus, animals of larger size, with teeth 

 reduced to 40 by the loss of 4 incisors, and like the foregoing, 

 comprising long-jawed types ; and the third family, the famous 

 Anaptomorphidae of Cope, short -jawed, very progressive types, 

 with 36 to 32 teeth, the premolar series being reduced. The 

 identification of these families with the Eocene Adapidis or with 

 Necrole77mr of Europe is not sustained. The Hypsodontidae and 

 Notharctidae are well distinguished by sexituberculate superior 

 molars. 



Dr. Hay called attention to the fact that for a long time 

 there has been much discussion regarding the origin of the 

 elements entering into the shell of turtles. As to the bones 

 known as costal plates, the great majority of anatomists have 

 held that they have resulted from the union oi dermal bones 

 with the underlying ribs ; the neural plates from the union of 

 dermal bones with the neural arches. Recently Goette has 

 studied the development of the costals and neurals of the 

 young of Chelone squauiata. He finds that the whole cos- 



