116 BULLETIN 99, UNITED STATES NATIONAL MUSEUM. 



Genus ACOMYS Geoffroy. 



1838. Acomys I. Geoffroy, Ann. Sci. Nat., Paris, ser. 2, vol. 10, p. 126. (^1. 

 cahirinus.) 



The spiny mice of this genus appear to be very local in distribution 

 and large parts of East Africa are unrepresented by specimens. In 

 some favorable localities, as in the Northern Guaso Nyiro district, 

 three, if not four, distinct species are found in one vicinity and the 

 animals are abundant. 



For detailed measurements of specimens see pages 119-121. 



ACOMYS WITHERBYI de Winton. ' 



1901. Acomys wit.herbyi de Winton, Novit. Zool., vol. 8, p. 400. December 31. 



(El Kowa, Sudan; type in British Museum.) 

 1905. Acomys witherbyi Schwann, Novit. Zool., vol. 12, p. 4. January. 



Specimen.— One, as follows : 



Sudan: Naikhala (Rothschild). 



Dr. Glover M. Allen ^ has suggested the probable identity of this 

 species with Acomys cineraceus Heuglin and Fitzinger, described from 

 Doka, eastern Sennar, between the Atbara and the Rahad Rivers. 



ACOMYS HYSTRELLA Heller. 



Plate 31. 

 1911. Acomys hystrella Heller, Smithsonian Misc. Coll., vol. 56, No. 17, p. 33. 

 February 28. (Nimule, Uganda; type in U. S. Nat. Mus.) 



Specimens. — Thirty-seven, from localities as follows : 

 Uganda: Ledgus, 5 in alcohol (Loring) ; Nimule, 32, including 9 

 in alcohol and 16 odd skulls (Loring). 



ACOMYS IGNITUS IGNITUS Doilman. 



1910. Acomys ignilus Dollman, Ann. and Mag. Nat. Hist., ser. 8, vol. 6, p. 1^29. 



August. (Voi, British East Africa; type in British Museum.) 



Specimens. — Thirty-two, from the following localities: 

 British East Africa: Changamwe, 5, including 4 in alcohol 

 (Mearns); Ma.ji-ya-chumvi, 2 (Heller); Mariakani, 4, including 2 

 in alcohol (Heller) ; Mazeras, 9, including 4 in alcohol (Heller) ; 

 Mtoto Andei, 6, including 3 in alcohol (Heller); Voi, 6 (Heller). 



Doctor Mearns notes of an adult male from Changamwe: ''Iris very 

 dark brown." At Voi on October 28, Heller found females with one and 

 two large embryos; at Mariakani, January 1, with one embryo; and 

 at Mtoto Andei, April 6, one very large embryo which is preserved 

 in alcohol. 



ACOMYS IGNITUS KEMPI DoUman. 



1911. Acomys kempi Dollman, Ann. and Mag. Nat. Hist., ser. 8, vol. 8, p. 125 



July. (Chanler Falls, Northern Guaso Nyiro, British East Africa; typd 

 in British Museum.) 

 1914. Acomys i[gnitus] kempi Dollman, Ann. and Mag. Nat. Hist., ser. 8, vol. 14, 

 p. 487. December. 



1 Bull. Mus ?omp. Zool. Harvard, vol. 58, p. 329. July, 1914. 



