No. 14. — New African Rodents. By Glover M. Allen. In a previous paper (Bull. M. C. Z., 1911, 54, p. 321-331) I have reported on the bats collected in British East Africa during the sum-mer of 1909 by Dr. William Lord Smith, Mr. Gorham Brooks, and myself. In working out the other small mammals obtained by our expedition, several unnamed forms have been found and these, as well as a dormouse from the Cameroon, presented by Dr. Thomas Barbour, are described as new. The new mammals obtained in East Africa are all from the northern Guaso Nyiro, northwest of Mt. Kenia, where as a result of the arid plateau conditions many of the species are represented by local forms of less intense coloration than their relatives of the coastal lowlands. A number of these have already been described by Thomas, Dollman, and others. The recent intensive study of the small mammals of Africa has shown not only a surprising wealth of species but also an immense amount of local varieties of these, which are the result of response to the greatly diversified physical conditions. This was strongly im-pressed upon us even in the comparatively short circuit covered to the north and west of Mt. Kenia, and thence to Nairobi and the coast. Dry rocky and bushy country succeeds fertile and well watered low-land, papyrus swamp gives place to broad flat plains, well grassed perhaps, or again, arid and grown up with xerophytic vegetation, according to the character of the soil. Crossing a divide brings one into deep wet forests whose stillness awes even the lightsome Swahili porters into silence, while the higher mountain peaks even under the equator reach an altitude of everlasting snow with alpine meadows below their glaciers. Each variety of country has its characteristic set of inhabitants and these again differ locally. Among the species here described, the most interesting is perhaps a naked burrowing rodent of the genus Heterocephalus, hitherto unrecorded outside of Abyssinia and Somaliland. It is another of those northeastern types that find their southwestern limits along the Guaso Nyiro. From this locality also, a dormouse (Graphiurus) is apparently for the first time recorded. It seems to be a local race confined to the scanty tree growth which forms a narrow border along the streams. The dark colored, small eared pygmy dormouse from the Cameroon is also of unusual interest.
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