194 TEN years' progress in vertebrate paleontology 



more primitive in its dentition, is distinguished from the living Micro- 

 gale of Madagascar chiefly by the greater external flattening and en- 

 largement of the ,sqiiamosal. 



Of the Oligocene Leptictidse, Doiiglass^^ has described some fine skulls 

 and portions of the post-cranial skeleton. In the Erinaceidae the genus 

 Proterix of Matthew^^ connects the hedgehogs with the Leptictidae. 

 Among the Talpidae ^tatthew^^ has described the skull of the Upper 

 Oligocene genus Proscalops, and to this family he has very provisionally 

 referred a large variety of teeth which are described and figured in his 

 important monograph on the Carnivora and Insectivora of the Bridger 

 Basin.^* One of these specimens, the type of Entomolestes grangeri 

 Matthew, so far as indicated by the dentition, is structurally ancestral 

 to the Tupaiidse. 



The genus Pantohstes, from the Bridger Eocene, founded by Cope on 

 very scant material and referred by him to the Artiodactyla, has been 

 redescribed from much better material by Matthew,^^ who refers the 

 Pantolestidae to the Insectivora, and shows that they combine Insectivore, 

 Creodont, and Pinniped features. 



Another puzzling synthetic type referred to the Insectivora is the 

 Eocene Hyopsodus, a form which during the last ten years has become 

 much better known through the researches of Osborn,^^ Wortman,^^ and 

 especially of Matthew.^^ These three authors have also discussed the posi- 

 tion of the Mixodectidse, and the probable conclusion is that this family 

 is not related to the rodents, but is either lemuroid or "insectivore." Pos- 

 sibly related to the Mixodectidge is the family Apatemyidse of Matthew,^^ 

 known from teeth and jaws from the Bridger Basin. 



If all these doubtful groups are to be included in the single order In- 

 sectivora, then the boundaries of that order become rather uncertain and 

 the exact relationships of the Pantolestoidea, Hyopsodonta, and Mixo- 

 dectidae to the Lipotyphla, Menotyphla, and other groups constitute a 

 promising field for future study. 



Primates 

 The varied Primates of the American Eocene, known chiefly from 



^ Mem. Caraegie Mns.. vol. ii. no. 5, l!)0(i. pp. 203-1223. pi. xxii. 



3a Bull. Amer. Mns. Nat. Hist., vol. xix, 1008. pp. 227-220. 



"Mem. Amer. Mus. Nat. Hist., vol. Ix, pt. vi. 1000. pi. xlix. fig. 5, pi. 11, figs. 3, 4. 



8* Ibid., pp. 54.3-.54fi. 



««Mem. Amer. Mus. Nat. Hist., vol. ix. pt. vi, 1000, pp. 522-534. 



38 Bull. Amer. Mus. Nat. Hist., vol. xvi. pp. lGO-214. 



»TAmep. Jour. Set., vol. 15, 1903, pp. 162-163. 



^ Mem. Amer. Mus. Nat. Hist., vol, ix, pt. vi, 1009, pp. 508-522. 



8° Ibid., pp. 543-546. 



