1896.] NATURAL SCIENCES OF PHILADELPHIA. 535 



Specimens : Nos. 3,820, 3,821, 3,822, 3,823, 3,824, 3,825, 3,920 : ^ 



5 ^ s, 2 9 s. 



42. Dendromys mesomelas (Brants). Long-tailed Tree Mouse. 



Three Dendromys, all apparently taken at Sheikh Mahomet, were 

 presented to the Academy of Natural Sciences of Philadelpliia by 

 Dr. Smith. Two of these, a half-grown young (No. 3,876) and 

 an adult male (No. 3,874), are in spirits; the third, an adult 

 male (No. 3,853), is a finely prepared skin with skull, and field meas- 

 urements taken by the collector. The two adults correspond so ex- 

 actly with Smith's beautiful plate" of D. typicus, in both color 

 and dimensions, I am unable to note any differences of even sub- 

 specific value. The fact that typicus is a South African species 

 would lead to the supposition that the Galla animal diflfered there- 

 from. In the absence of specimens for comparison, these will be 

 classed under mesomelas, Wagner, Heuglin and Trouessart agreeing 

 that typicus is a synonym of that species. Matschie^ names the 

 long- tailed Dendromys of East Africa D.piimilio Wagner, quoting 

 " Munch, gel. Anz., XII, 1820, p. 437." I am unable to find this 

 publication, but would suppose some mistake, as Wagner states 

 three times in his description of piimilio in Weigmanu's Archiv. fur 

 Naturgesehichte, 1841, p. 135, that it is a "new species," no refer- 

 ence being made to a previous description. The chief distinction 

 between jyumilio and mesomelas (if any, Trouessart and Heuglin 

 considering them the same) is the absence of the dark dorsal stripe 

 in the former. 



From D. mystacalis Heugl.,-' of Abyssinia, the Sheikh Mahomet 

 specimens are distinguished by greater size, relatively longer and 

 less hairy tail and the presence of the dark dorsal stripe. 



In No. 3,853 (I.e.) the total length is 177 mm.; tail, 100; hind 

 foot, 21. In No. 3,874 these measurements are respectively 163, 92 

 and 22 ; the ear from crown is 11.5. 



43. Dendromys sp. 



A young spirit specimen (No. 3,876), whose skull shows it to be 

 about two-thirds grown, diflfers so markedly in the black color of 

 the ears and orbital region and the white spot at the bases of ears 

 and the tail being only equal to the head and body in length, that 

 there is little doubt of its belonging to a diflferent species from the 



^i Illiist. Zool. S. Afr., 1849, pi. 34, fig. 1. 



2= Die Saug. Ost Afr., 1895, p. 49. 



23 Nov. Act. Acad. Cse-s. Leop., 1863 (Sept. 1862), p. 5. 



