1910.] Onjchropus; Manis. 337 



lower Ungulata has been supported by Elliot Smith, Lonnberg and Weber. 

 Elliot Smith (1898, p. 277) concludes that in its brain characters Orycteropus 

 "is distinctly comparable with a primitive Ungulate type" from which it 

 differs only in the high development of the olfactory parts. The astragalus 

 also, both with regard to its facets and to its general conformation, rather 

 resembles the astragalus of the more primitive Notoungulata. (C/. Ame- 

 ghino, 1906.) 



Lonnberg (1906) controverts Owen's opinion that each cheek tooth is a 

 complex of separate denticles analogous to that in certain Selachians, and 

 also dissents from Weber's opinion (1904, p. 417) that it formerly had 

 elaborate enamel folds. He believes that the ancestral Tubulidentate had 

 low-crowned, simple-rooted cheek teeth, with reduced enamel. The pulp 

 originally had short, irregularly branched canals, which entered the dentine, 

 a condition preserved in part in the small, less specialized anterior teeth; 

 the crown of the tooth soon wore off but the roots lengthened and gave rise to 

 the bicolumnar molars of Orycteropus; while, with increasing hypsodonty, 

 the branching pulp-tubules became parallel. If this theory be true the cheek 

 teeth offer no obstacle to the hypothesis that the Tubulidentata are derived 

 from the Condylarthra (Lonnberg). However, about the only direct points 

 of resemblances to that group are the dorso-lumbar number of 21 and the 

 characters of the astragalus. At any rate, the prevailing resemblances of 

 Orycteropus as regards the brain, dentition and astragalus seem to be with 

 the Protungulates rather than with the Insectivores and Creodonts; although 

 distant relationship both with the Ganodonta and Xenarthra is also possible. 



The Pholidota (Manid^). 



The anatomy and development of Manis, as well as its systematic and 

 phyletic isolation have been thoroughly discussed by Weber (1894) in his 

 monograph on that animal and in his 'Die Saugetiere' (pp. 420-429). 



Manis differs from Orycteropus in the development of true scales,^ in the 

 convoluted brain, in the peculiar characters of the digestive tract, in the 

 bicornuate uterus, in the relations of the testicle, which lies outside of 

 the inguinal canal, and in the very large yolk sack and diffuse placenta; while 

 the skull and skeleton offer equally distinctive details. 



The Pholidota are distinguished from the Xenarthra by many characters 

 of the reproductive organs and placentation. In the skull the strong general 

 resemblances to Myrmecophaga are interpreted by Weber (1904, p. 422) 

 as convergent adaptations to ant-eating habits and are accompanied by deep 

 seated differences: e. g., the lachrymal is reduced and not pierced by the 



1 See footnote 1, page 146. 



