EAST AFRICAN MAMMALS IN NATIONAL MUSEUM. 57 



Specimens. — Four, from localities as follows: 



British East Africa: Mount Sagalla, 1 (Heller); Mount Umengo, 

 1 (Heller); Ndi, 2 (Heller). 



The female collected on Mount Sagalla, November 19, contained 

 seven large embryos. Several statements in the original account of 

 this form need correction. The skins are distinctly darker, not 

 lighter, in dorsal coloration than skins of true hildegardese; the 

 under parts are not more "whitish;" the mesopter3'goid fossa is 

 distinctly wider, not narrower, in three out of four of the skulls, 

 than in our two skulls of hildegardese; the tail is hardly ''quite hair- 

 less," but is well clothed with light colored hairs longer than the 

 width of two scale rows. The three paratypes do not agree closely 

 with the type in color or skull characters. There is such an extra- 

 ordinary amount of individual variation among the specimens that 

 I have rather doubted their conspecitic identity. This is especially 

 true of the skulls, where the variation in size, breadth of rostrum^ 

 and other minor characters is unusual. It would be interesting to 

 study a large series of these mammals from some one locaUty. 



Genus THAMNOMYS Thomas. 



1907. Thamnomys Thomas, Ann and Mag. Nat. Hist., ser. 7, vol. 19, p. 121. 



January. (T. venustus.) 

 1915. Grammomys Thomas, Ann. and Mag. Nat. Hist., ser. 8, vol. 16, p. 150. 

 August. (T. dolichurus.) 



All the forms of Thamnomys included in our East African collec- 

 tions belong to that section of the genus which has been named 

 Grammomys by Thomas. The characters on which the genus Gram- 

 momys is based^ seem altogether too slight for even subgeneric recog- 

 nition. 



For measurements of specimens of Thamnomys see pages 59-61. 



THAMNOMYS SURDASTER SURDASTER Thomas and Wronghton. 



1892. Mus arborarius True, Proc. U. S. Nat. Mus., vol. 15, p. 459. (Not of 

 Peters. )2 



1908. Thamnomys sxirdaster Thomas and Wroughton, Proc. Zool. Soc. London, 



1908, p. 550. (Zomba, British Central Africa; type in British Museum.) 



Specimens. — Three, as follows : 



German East Africa: Mount Kilimanjaro (Abbott). 



No specimens of typical surdaster are in the National Museum col- 

 lection, but Mr. Thomas has referred the Kilimanjaro form to this 

 species^ and remarks that it agrees in color with examples from 

 Nyasa. 



1 "Like Thamnomys, but with the postero-intemal or 'a;' cusp of the first and second molars reduced 

 to a mere connecting ridge nmning from the inner cusp of the median lamina to the hinder point of the 

 tooth."— Thomas, Ann. and Mag. Nat. Hist., ser. 8, vol. 16, p. 150. August, 1915. 



2 Regarding the identification of Mus arborarius Peters, see Thomas and Wroughton, Proc. Zool. Soc, 

 London, 1908, p. 548. 



' Ann. and Mag. Nat. Hist., ser. 8, vol. 16, p. 314. September, 1910. 



