EAST AFEICAN MAMMALS IN NATIONAL MUSEUM. 77 



The specimen from Mtoto Andei appears to extend the known 

 range of this rat in British East Africa. I am not aware of a previous 

 record from north of the Taita Hills. 



According to Mr. Thomas's classification of the groups of African 

 Rattus, this species is a member of the subgenus JUthomys, along with 

 the forms of Rattus Icaiseri listed above. 



RATTUS TULLBERGI JACKSONI (de Winlon). 



1897. Mu$ jacksoni de Winton, Ann. and Mag. Nat. Hist., eer. 6, vol. 20, p. 318. 



September. (Entebbe, Uganda; type in British Museum.) 

 1910. Epimys jacksoni Roosevelt, African Game Trails, Amer. ed.. p. 473; 



London ed., p. 485. 

 1914. Epimys tulbergi endorohm Frick, Ann. Carnegie Mus., vol. 9, p. 8, pi. 2. 



June 6. (Not Epimys endorohse Heller.) 



Specimens. — One hundred and thirteen, from localities as follows: 



Uganda: Kabula Muliro, 4 (Loring); Kampala, 3 (Heller); Ki- 

 kandwa, 1 (Loring) ; Kisimbiri, 1 (Loring) . 



British East Africa: Aberdare Mountains, 2 (Heller); Guas 

 Ngishu Plateau, 12 and 30 mOes north of Ravine, 5 (Heller) ; Kaimosi, 

 55, including 16 in alcohol (Heller, Turner); Kakumega, 2 (Heller); 

 Kisumu, 2 (Heller); Lukosa Eiver (Yala River), 3, including 1 in 

 alcohol (Heller); Mount Kenia, 23, including 22 in alcohol (Heller, 

 Loring); Nyuki River, 2 in alcohol (Heller); Ravine, 1 in alcohol 

 (Heller); Wambugu, 9 (Loring). 



In the series from Kaimosi are a few puzzling specimens which, 

 after some hesitation, I have placed with this species. While the 

 skulls of all other specimens listed above agree in presenting a very- 

 uniform appearance, these few skulls — about a dozen in all — differ 

 in having shorter palatine slits, not reaching plane of first molar, 

 and in almost complete absence of supraorbital ridges. Otherwise 

 they show no distinguishing characters and the skins are absolutely 

 inseparable from other skins in the Kaimosi series and from other 

 parts of the range of jacksoni. 



Heller found a female specimen at Kakumega February 15 with 

 3 fetuses; and two at Kaimosi, January 27 and February 3, each with 

 four small embryos. 



Many skins of jaclcsoni are indistinguishable by external characters 

 from specimens of true tuUbergi from West Africa. 



For measurements of specimens of the subspecies of Rattus tuUbergi 

 see page 78. 



RATTUS TULLBERGI PEROMYSCUS (Heller). 



Plate 20. 



1909. Mus peromyscus Heller, Smithsonian Misc. Coll., vol. 52, pt. 4, p. 472. 



November 13. (Njoro O Nyiro, Sotik, British East Africa; type in U. S. 

 Nat. Mus.) 



1910. Epimys peromyscus Roosevelt, African Game Trails, Amer. ed., pp. 473, 



477, and 484 (part); London ed., pp. 485, 489, and 495 (part). 



