EAST AFRICAN MAMMALS IN NATIONAL. MUSEUM. 69 



worn (Amer. Mus. Nat. Hist. 27882) follow: Condylobasal length, 

 30.5, 32.3; breadth of bramcase, 15, — ; mastoid breadth, 14.2, 

 14.4; length of nasals, 11.5, 11.8; interorbital breadth, 5.4, 5.5; 

 upper tooth row, alveoli, 6.4, 6.5. Both skulls are so young that 

 they would ordinarily be excluded from tables of measurements of 

 fully grown individuals. 



One of our specimens from Juja Farm has been submitted to 

 Doctor Lonnberg for comparison with the type of Epimys jujensis. 

 Doctor Lonnberg writes that these specimens are very similar and 

 probably belong to the same species. The Juja Farm specimens 

 are unquestionably identical with Allen's Mus 'kijabius. 



RATTUS NIGRICAUDA LORINGI (HeUer). 



Plate 20. 



1909. Thamnomys loringi Heller, Smithsonian Misc. Coll., vol. 52, pt. 4, p. 471. 



November 13. (Lake Naivasha, British East Africa; type in U. S. 

 Nat. Mus.) 



1910. Mus loringi Osgood, Ann. and Mag. Nat. tlist., eer. 8, vol. 5, p. 277. 



March. 

 1910. Thamnomys loringi Roosevelt, African Game Trails, Amer. ed., pp. 473, 



478; London ed., pp. 485, 490. 

 1910. Thamnomus loringi Roosevelt, African Game Trails, Amer. ed., p. 484; 



London ed., p. 495. 



Specimens. — ^Twenty-two, from localities as follows: 



British East Africa : Lake Naivasha, 6 (Loring) ; Lime Springs, 

 Sotik, 7, including 1 in alcohol (Heller); Loita Plains, 1 (Heller); 

 Naivasha Station, 7 (Loring); Telek River, Sotik, 1 (Heller). 



Specimens from the Sotik appear to be slightly grayer, less reddish, 

 above; and with less clear slate color in the underfur of the lower 

 parts than skins from the type region around Naivasha; but the 

 difference is hardly sufficient to separate a race, especially as the 

 series from the two localities were collected at different seasons. 



Heller notes four embryos in a female from Loita Plains, April 27. 

 Labels of two specimens from Lime Springs are marked: "Caught 

 on limbs of acacia." Roosevelt and HeUer ' have written of these 

 masked tree-rats: 



In the Rift Valley; common around Naivasha. Arboreal and nocturnal. Much 

 the habits of our neotoma, but do not build large nests. Build nests about 6 inches 

 in diameter, made of sticks, placed in the branches of thorn-trees; also in burrows 

 near the bottom of the trunks; runways lead from the trees containing the nests to 

 the burrows. Trapped on the ground and in traps set in notches of the trees. 



For measurements of specimens see page 70. 



' Appendix B, African Game Trails, Amer. ed., p. 478. 1910. 



