18/6.] DR. A. GUNTHER ON NEW MAMMALS. 743 



I know the two latter only. Although readily distinguished in 

 the adult state, they are sufficiently similar when young to render 

 the determination of examples, the origin of which is unknown, a 

 matter of some uncertainty. The skulls, however, show constant, 

 though slight, distinctive characters. 



In Atherura macrura (fig. 3, p. 742) the foramina incisiva are 

 extremely narrow slits which run in an almost parallel direction, and 

 are very close together. The palatal notch advances far forwards, 

 to the level of the third molar. The alisphenoid is very thin, but 

 slightly bent outwards. 



In Atherura africana (fig. 4, p. 742) the incisive foramina are 

 narrow, but conspicuously wider and much more distant than in the 

 Malayan species, and divergent behind. The roof of the palate 

 extends far backwards, its hind margin being behind the level of the 

 last molar. The alisphenoid forms a broad and rather thickened 

 ramus, bent outwards and much produced backwards. 



4. On some new Mammals from Tropical America. 



Hapale leucopus. (Plate LXXII.) 



Upper and lateral parts of the body covered with silky hair of 

 moderate length and brownish-grey colour, darkest on the nape of the 

 neck and occiput ; face and head with short sparse white hair. Ears 

 large, naked, without tuft. Throat greyish brown ; lower parts of 

 the body and inside of the legs rusty red ; forearm, hands, and feet 

 white. Tail short-haired, blackish or black, with white extremity. 



The female differs from the male in the hairs of the upper parts 

 having silvery white tips. 



Length of head and body 11^ in., of tail 14 l 7 in. 



Number of vertebras: cervical 7, dorsal 12, lumbar 7, sacral 3, 

 caudal 31-33. 



Medellin. Several specimens, identical in coloration, collected by 

 Mr. T. K. Salmon near Medellin, Antiocpua, U. S. of Columbia. 



Dactylomys typtjs (Is. Geoffr.). 



We have received two fine skins of this rare Rodent, unfortunately 

 without skulls, from the Rio Napo. 



the occurrence on the coast of West Africa of freshwater fishes previously 

 considered to be exclusively typical of the Indian region. 



That these instances escaped the notice of naturalists who have recently dis- 

 cussed the relations of the African and Indian faunas is to me less surprising 

 than the omission of a not less singular fact, viz. the reappearance of Atherura 

 on the West-African coast. It strongly confirms Mr. Wallace's view that there 

 is present, in the Mammals and Birds of West Africa, a special Oriental or even 

 Malayan element (Geogr. Distrib. i. p. 263). Instances of this kind appear to 

 me to be of infinitely greater weight in solving the problem of the mode of 

 dispersion of animals over the globe (or their genesis) than deductions drawn 

 from lists of genera vaguely or artificially defined. On this occasion I may also 

 be allowed to refer to, and thus, perhaps, save from oblivion, some remarks 

 in Rept. Brit. Ind. Introduct. p. viii, in which, I believe, for the first time, the 

 occurrence of African Reptilian types in the Indian Region has been distinctly 

 stated. 



49* 



