42 Mamm. 
II. MAMMALIA. 
C. Didelphyid^l 
Didelphys ( Micoureus ) canescens , n. sp., J. A. Allen, Bull. Amer. Mus. v, 
p. 235, Tehuantepec, Mexico. 
Didelphys Tcoseriti , n. sp., Iiiering, in paper quoted supra , p. 10. 
10. MONO TR EM A TA . 
For homologies of bones of shoulder-girdle, see Howes, suprc l, p. 10, and 
Lydekkeu, p. 12, the former author also dealing with the structure 
of the pelvis. Koken, Zeitschr. deutsch. geol. Ges. xlv, pp. 313 
et seqq., also enters into the discussion, and considers that the cora- 
coid process of Placentals represents the amalgamated coracoid and 
precoracoid of Reptiles and Amphibiaus. He refuses to admit an 
homology between the precoracoid of Dicynodon and the epicoracoid 
of the Monotremuta , remarking that the latter is a true epicoracoid 
plus an omosternum. 
In the course of their observations on the structure and histology of the 
muzzle of Ornithorhynchus , Wilson & Martin (supra, p. 22) show 
that the beak is covered with soft delicate skin, like that of the nose 
of a dog, and that the whole structure is most highly supplied with 
tactile organs. The snout is supported on cartilage supposed to be a 
vestige of the primitive chondro-cranium. 
^ f Adiastaltus habilis , n. g. & sp., Amegiiino, Rev. Jard. Zool. B. Ayres, 
i, p. 77, Tertiary, Patagonia. 
* f Anathitus revelator t u. g. & sp., Ameghino, t. c. p. 78, ibid. 
11. f MULTITUBERGULATA. 
Ameghino, Rev. Gen. Sci. iv, pp. 77-81, discusses the relations of Micro - 
biotherium , Abderites , and certain other allied South American 
Tertiary forms to the Multituberculata of the United States. Both 
groups are considered to bo very closely allied, but as the Nootropical 
forms do not exhibit any marked multituberculism, they are regarded 
as connecting the North American types with the Diprotodout Mar- 
supials. The author is of opinion that Bolodon is founded upon the 
upper molars of Plagiaulax. 
For the Upper Cretaceous Plagiaulacidce of the Laramie beds, see Osborn, 
suprd , p. 17. 
