1902.] MAMMALS FROM TRIPOLI. 9 



alike in size and general characters. Indeed it is almost impos- 

 sible to distinguish them extei'nally from each other, thouo-h 

 M. shaiai has on the average a rather duller or more drab tone 

 than M. schoushoei. Nor are the skulls less alike, except for the 

 chai'acteristic difi'erence in the size of the bull*. 



11. Merioxes schousboei Loche. 



Gerhillus schousboei Loche, Expl. Sci. Alg., Mamm. p. 105 (1867), 



20.26.33. Ain Hammam. 28/4-2/5/1. 



40. Tamari-Ferdjan. 5/5/1. 



53. 54. Oum el Abid. 13-14/5/1. 



60. Zighen. 15/5/1. 



72. Serir, Mursuk. 1/6/1. 



88. Koshby. 16/6/1. 



93.94.96.97. Ferd'jan. 19-21/6/1. 



112. W. Agarib. 3/7/1. 



115.116. W. Wagis. 7/7/1. 



121-135. 138-142. G. Limhersuk. 14-19/7/1. 



143-144. Gebel Binsertia. 20/7/1. 



163. Sidi Sweya. 5/8/1. 



Although the group is too difficult to be worked out in detail, 

 the name adopted seems the best to use for the Barbary repi-e- 

 sentative of the M. erijthrurus-grou]). Its reference to that 

 group is accepted on the authority of Lataste. 



12. PSAMMOMYS TRirOLITAXUS, Sp. n. 



155. W. Aggar. 25/7/1. 



160. W. Cheggar. 28/7/1. 



161. Bou Cheifa. 1/8/1. 



Size faii'ly large, though smaller than in P. algiricus. Median 

 facial and dorsal area dark buffy (something between " wood- 

 brown" and "pinkish-buff"). Sides and belly yellow. Cheeks 

 pale greyish. Upper surface of hands and feet yellowish white. 

 Tail strong buffy, the crest and pencil black ; tei-minal haii-s of 

 pencil attaining about 14 mm. 



SkuU smaller and moi-e delicately built than in the other large 

 species, though markedly larger than in P. roadairei. See 

 dimensions below. Bullae small and narrow ; the part that 

 appears on the top of the squamosal particularly small. 



Dimensions of the type : — 



Head and body 157 mm. ; tail 135 ; hind foot 35 ; ear 14. 



Skull — greatest length 41-5; basila,r length 34-3 ; zygomatic 

 breadth 24; nasals 15-3; interorbital breadth 6-5; least breadth 

 between ridges on parietals 10-5 ; breadth between anterior lips 

 of meatus 24 ; length of exposed upper area of bulla 5*4 ; diastema 

 12-1 ; greatest diameter of bulla 14-3, lesser diameter, from 

 antei-ior lip of meatus, 11*5 ; length of upper molar series 6'8. 



Typical locality. Bou Cheifa, on the coast. 



Type, Old male. No. 161. Killed 1 August, 1901. 



