160 



BULLETIN" 99, UNITED STATES NATIONAL MUSEUM. 



HETEROCEPHALUS GLABER RuppeU. 



Plates 6, 7. 

 1842. Heterocephalus glaber Ruppell, Mus. Senckenberg, vol. 3, Heft 2, p. 99. 



(Schoa, Abyssinia; type in Senckenberg Museum, Frankfort.) 

 1903. Heterocephalus ansorgei Thomas, Proc. Zool. Soc. London, 1903, vol. 2, p. 



336. (Between Ngomeni and Kenani, Britisb East Africa; type in 



British Museum.) 

 1912. Heterocephalus stygius G. M. Allen, Bull. Mus. Comp. Zool., vol. 54, p. 



444. April. (Neuman's Boma, Northern Guaso Nyiro, British East 



Africa; type in Mus. Comparative Zoology, Harvard University.) 

 1912. Heterocephalus glaber progrediens Lonnberg, Kungl. Sv. Vet. Akad. Handl., 



vol. 48, No. 5, p. 102. (Thornbush country north of Northern Guaso 



Nyiro, British East Africa; type in R. Nat. Hist. Mus., Stockholm.) 



Specimens. — Thirteen, from localities as follows: 



Italian Somali: Lugli, 1 iu alcohol (Bottego). » 



British East Africa: Archer's Post, 3 (Heller); Lakiundu 

 River, 1 (Heller) ; Longaya Water, Marsabit Road, 1 (Heller) ; 

 Merelle Water, Marsabit Road, 6, including 4 in alcohol (Heller) ; 

 Northern Guaso Nyiro River, 30 miltss east of falls, 1 (Percival). 



In Heller's field journal of the Rainey Expedition I find the fol- 

 lowing interesting notes on naked rats: 



Longaya Water: This morning near camp I saw several of the Heterocephalus throw- 

 ing dirt out of their burrows. Little puffs of sand were coming out at intervals. The 

 animal could not be seen and was apparently below the mouth of the burrow. This 

 was about 8 a. m., and at 9 a. m. I again went out to snare some, but found them all 

 quiet. They are apparently active only in the early morning. At sundown more 

 were seen working. Went out at 9 p. m. with the headlight but found none at work 

 where holes were numerous. Caught one during the night in a trap. Merelle Water: 

 At 5 p. m. Isawseveral Heterocephalus t\ixom.n.g sand outof the burrows. I stood over 

 one of the holes and watched. The animal pushed the dirt to the entrance with his 

 head, then turned about and with his hind feet threw the dirt out, in a rapid puffy 

 fashion, vertically, so that in falling it made a funnel-shaped pile about the hole. 

 While he was thus throwing out the earth his tail could be seen wagging back and 

 forth. Archer's post: As we were approaching camp I saw one of the naked mole 

 rats throwing out sand in the bright sunshine. They seem [after all] to have no defi- 

 nite time for work. 



Measurements of specimens of Heterocephalus glaber from British East Africa. 



