INSECTIVORES 193 



From a detailed analysis of the osteology and other features of the 

 various families it was concluded that Weber was entirely right in 

 adopting Haeckel's division of the Insectivora into two sharply separated 

 suborders, namely, the Lipotyphla, embracing the Zalambdodonts, Lep- 

 tictids, Erinaceids, Moles, and Shrews, and the Menotyphla, including 

 the Tupaiidse and Macroscelididse. It was further shown that the Meno- 

 typhla approach the Lemuroids so closely that possibly they may be truly 

 related to the Primates, although the possibilities of convergence must 

 not be forgotten. In the same work the Chrysochlorids were carefully 

 compared with the Marsupial "mole" Notoryctes, and the conclusion of 

 Weber and Leche was confirmed that the numerous resemblances be- 

 tween these two families were very largely secondary. The confusing 

 homologies of the molar cusps in the different families were discussed. 

 By setting aside the. specializations peculiar to the different families nnd 

 by putting together the characters regarded as primitive, an attempt was 

 made to reconstruct the primitive Insectivore, and it Avas concluded that 

 such a type would be structurally ancestral to the Primates, Creodonts, 

 Condylarths, Ungulates and related groups, and possibly also to the Ko- 

 dents. Matthew's view^^ that the stem Placentals were arboreal forms 

 was supported. The Tillqdonts also were referred to the Insectivore- 

 Creodont stem and their supposed connection with the rodents was 

 denied. 



To our knoA\'ledge of Tertiary Insectivora very notable additions have 

 been made. Douglas,^^ under the name Xenotlierium, described in 1906 

 a small skull from the Oligocene of Montana which unfortunately lacked 

 the teeth. This genus was later referred by Matthew^^ to the Chryso- 

 chloridge, along with certain other little-known forms from the Titano- 

 therium beds. That Xenotlierium is a Chrysochloroid is shown by many 

 features, but especially by the characteristic form and relations of the 

 auditory bulla. The extinct and previously little known Patagonian 

 genus Necrolestes of Ameghino was more fully described in 19<H by 

 Professor Scott, '^ who showed that it is probably an offshoot from some 

 early member of the family which was at the same time the ancestor of 

 Chrysochloris. 



The paleogoogra])hical bearing of these discoveries is of considerable 

 importance, and not less so is the description by Matthew^^ of the genus 

 Apternodus, a member of the Centetidge. Apternodus, while sli.gfhtly 



=« American Naturalist, 1004. pp. 811-818. 



^ Mem. Carnesio Mus., vol. ii. no. 5, pp. 203-223, pi. xxii. 



28 Science, n. s.. vol. xxiv, 1906. pp. 786-788. 



29 Rept. Princeton Univ. Exped. to Pafajjonia, vol. v, pp. 365,38.3. pi. Ixiv, figs. 1-5. 

 «>Bull. Amer. Mus. Nat. Hist., vol. xix, 1903, p. 225; ibid., vol. xxvlll, 1910, pp. 33- 



36, pi. tI. 



