30 BULLETIN 99, UNITED STATES NATIONAL MUSEUM. 



Specimens. — Thirty, from localities as follows: 



British East Africa: Kapiti Plains, 10, including three in alco- 

 hol (Loring); Suswa Plains, 1 (Heller); Ulukenia Hills, 19, including 

 5 in alcohol (Loring). 



This is a very slightly differentiated subspecies. In color it is 

 almost precisly as in true vidua, but the tail is lighter colored and 

 apparently never becomes blackish as in the coast form. In African 

 Game Trails, Roosevelt and Heller say of this form: 



Common on the Atlii Plains, in open ground at the foot of the hills. Live in short 

 grass, not bush. Nocturnal. Live in burrows, each burrow often possessing several 

 entrances, and sometimes several burrows, all inhabited l)y same animal, not com- 

 municating. 



Loring found four embryos, each 17 mm. long, in a female col- 

 lected November 28 at Ulukenia Hills. 



TATERA VICINA ICONICA Dollman. 



1911. Tatera iconica Dollman, Ann. and Mag. Nat. Hist., ser. 8, vol. 7, p. 521. 

 May. (Nyama Nyango, Northern Guaso Nyiro; type in British Museum.) 



Specimens. — Seventeen, from the following localities: 

 British East Africa: Isiola River, 3 in alcohol (Heller); Mount 

 Gargues, 4 (Heller) ; Mount Lololokwi, 2 (Heller) ; Northern Guaso 

 Nyiro River, 8, including 4 in alcohol, (Heller). 



This is another slight color subspecies of T. vlcina. There ap- 

 pear to be no skull characters to distinguish it from true vicina or 

 from potJiae, and the color difference is only average. Certain speci- 

 mens almost exactly match in every detail specimens of vichia, but 

 the series as a whole appears slightly paler with less indication of a 

 darker dorsal area. 



TATERA NIGRICAUDA NIGRICAUDA (Peters). 



1878. Gerbillus nigricaudus Peters, Mon.-ber. Kon. Akad. Wiss. Berlin, 1878, 

 p. 200. (Ndi, Taita, British East Africa; type in Berlin Museum.) 



Specimens. — Four, from localities as follows: 



British East Africa: Maji-ya-chumvi, 1 (Heller); Mtoto Andei, 

 2, including 1 in alcohol (Heller); Voi, 1 (Heller). 



Notwithstanding the great difference in the color of the tail between 

 typical examples of nigricauda and vicina, there are numerous young 

 examples which have been placed with the series of vicina which 

 might equally well be supposed to belong under nigricauda. I 

 can find no characters whatever to separate the two species except 

 the color of the tail, and as shovvm under remarks on Tatera vicina 

 vicina there is almost every intermediate stage in color pattern 

 between the lightest and darkest colored tails in that form; and the 

 step to the totally black tail of '' nigricauda" is small. 



The greatest skull length of Peters's type-specimen is given as 

 49 mm., and Wroughton records a specimen in the British Museum 



