420 Mr. O. Thomas on 



usual blackish, but so dark is the general colour that there is 

 little difference between the back and flanks. Under surface 

 greyish buffy. Hands and feet greyish brown, with a slight 

 tinge of buffy. Tail hairs ringed with black and dull buffy 

 white, some of them with tawny bases. 



Hob. Daru, 150 miles inland, Sierra Leone. 



Type. Male. B.M. no. 7. 7. 15. 4. Collected and pre- 

 sented by Capt. L. Murray, of the East Surrey Regiment. 

 Two specimens. 



Dipodillus brockmani, sp. n. 



Smaller than D. somalicus, with smaller teeth but larger 

 bullae. 



Size decidedly smaller than in D. somalicus, the only 

 known Somali species of Dipodillus. General colour rather 

 paler sandy than in that animal. No darker nose-spat. A 

 small white spot above each eye. Lighter patches behind 

 ears not very conspicuous. Fore limbs pure white, the line 

 of demarcation passing over the shoulder. Tail long, greyish 

 white, not sandy above, white below ; terminal crest little 

 developed, its longest hairs about 8-9 mm. 



Skull differing from that of D. somalicus in the direction 

 of Microdillus, being a little more bowed above, and with the 

 bulla? surpassing the occiput posteriorly. Interorbital region 

 not especially narrowed. Cranium convex above. Anterior 

 palatal foramina shorter than in somalicus. Bullae very 

 large for a Dipodillus, larger than in the larger D. somalicus, 

 closely approximated in the median line anteriorly, and pro- 

 jecting posteriorly beyond the occiput, a considerable portion 

 of this visible in an upper view of the skull. Teeth ex- 

 ceedingly small. 



Dimensions of the type (measured in the flesh) : — 



Head and body 76 mm. ; tail 117 ; hind foot 21 ; ear 11. 



Skull : greatest length 25 ; basilar length 17'5 ; nasals 9*5 ; 

 interorbital breadth 4*8 ; breadth of brain-case 125 ; ante- 

 rior palatine foramina 4' 7 ; greatest horizontal diameter of 

 bulla 10; upper molar series 3 1. 



Hub. Somaliland. Type from Burao, 85 miles S. of 

 Berbera. 



Type. Adult female. B.M. no. 10. 3. 27. 21. Original 

 number 255. Collected 21st December, 1909, and presented 

 by Dr. B. E. Drake-Brockman. Two specimens. 



This little Gerbil, which was recognized as new by its 

 captor, and is named after him, is readily distinguishable 

 from any of its allies by its comparatively large bullae, which 



