538 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



Acomys percivali Dollman 



Acomys percivali Dollman, Ann. Mag. Nat. Hist., ser. 8, vol. 8, p. 126, July, 1911. 

 (Chanler Falls, British East Africa.) 



SpEciaiENS Examined: Thirteen, from: Ikoto, 3 (1, AICZ); Torit, 

 1; Lafon, 60 miles north of Torit, 1 (MCZ); Mura, Lofit Hills, 1 

 (MCZ); Labalwa, 5 miles east of Torit, 7 (MCZ). 



Measurements: An adult male from Torit and an adult female 

 from Ikoto measure, respectively, as follows: Length of head and 

 body 97, 100; length of hind foot 15.5, 16; length of ear 14, 14; greatest 

 length of skull 26.6, 26.6; condyloincisive length 23.9, 24.0; crown 

 length of upper toothrow 4.3, 4.2; width of rostrum at level of antor- 

 bital foramen 2.9, 3.1; least interorbital width 4.7, 4.7; length of 

 nasals 10.6, 10.2; greatest width across zygomatic arches 12.7, ?. 



Remarks: This dark species of spiny mouse is readily distinguished 

 from A. vj. argillaceus bj" its much darker color and larger skull. It 

 may be distinguished from A. hystrella, with which it occurs, bj'^ its 

 darker color, shorter hind foot, relatively larger skuU, flatter braincase, 

 shorter, more constricted anterior palatine foramina, and the smaller 

 interpterygoid fossae. 



Acomys tcilsoni argillaceus Hinton and Kershaw 



Acotnys wilsoni argillaceus Hinton and Kershaw, Ann. Mag. Nat. Hist., ser. 9, 

 vol. 6, p. 101, July, 1920. (Mongalla.) 



Specimens Examined: Thirteen, from: Torit, 6 (3, MCZ) ; Ngaboli, 

 47 miles north of Torit, 1 (MCZ) ; Longairo, 20 miles east of Torit, 1 

 (MCZ);Malek, 5 (BM). 



Measurements: An adult male from Ngaboli and an adult female 

 from Torit measure, respectively, as follows: Length of head and 

 body 128, 118; length of tail 49, 45; length of hind foot 13, 12.5; 

 length of ear 10, 10; greatest length of skull 23.7, 22.5; condjdoincisive 

 length 21.6, 20.1; crown length of upper toothrow 3.7, 3.6; width of 

 rostrum at level of antorbital foramen 2.8, 2.7; least interorbital width 

 4.6, 4.2; greatest width across zygomatic arches 11.6, 11.3; length of 

 nasals 8.9, 8.7. 



Remarks: All of the above specimens agree in detail with the 

 type of argillaceus and differ from A. w. wilsoni and A. w. ahlutus in 

 a darker dorsal color. This darker dorsal color is obtained by the 

 lessening of the reddish subterminal bands and the lengthening of 

 the blackish terminal bands of the spines. This species may be 

 distinguished from other species of Acoimjs by its speckled appearance 

 dorsally. 



