8 MR. OLDFIELD THOMAS ON [May 6, 



No. 70, G. gerbii, comes from Beni Sliman, about 40 miles 

 south of Algiers. Tlierefore noii3li of the mountains, and within 

 the area of true G. camjjestris . 



No. 72, Psammo7m/s minutus, is possibly J), dodsoni, but the 

 name is unavailable," being based on the totally dijfferent Bipus 

 minutus Geoffr, 



No. 80, M'us chammrojjsis, is clearly a Mus, as its smooth 

 incisors testify. 



9. DiPODILLUS VIVAX, Sp. U. 



27. Ain Hammam. 29/4/1. 



66 Sebha. 19/5/1. 



Closely allied to the Egyptian D. qaadrimacalatus Lat. and 

 amcenusde Wint., which it no doubt replaces in Tripoli. 



Size as in D. amcemis. General colour above bright uniform 

 ochraceous buif, scarcely lined with brown. Belly and limbs 

 pure white. Upper whiskers brown, lower white. Usual white 

 face-marks well defined. Tail about as long as in D. amcenus, 

 pencilled above terminally, the hairs about 10 mm. in length; 

 pale fawn lined with brown above, the pencil-lines brown, below 

 paler, or whitish fawn. 



Skull very like that of Z>. amcenus, rather smaller than that of 

 D. quadrimactdatus ; differing from both by "its decidedly lai'ger 

 bullae, and the consequent nairowness of the basioccipital between 

 them. 



Dimensions of the type : — 



Head and body 75 mm. ; tail damaged (of the second specimen 

 106); hind foot *21; ear 12. 



Skull — greatest length 26*7; basilar length 19"7; zygomatic 

 breadth 14" 5; nasal 9*7; interorbital breadth 4'4 ; breadth of 

 brain-case 12*6; diastema' 6"7 ; palatal foramina 4"2 ; greatest 

 diameter of bullae lO'l ; length of upper molar series 3'2 ; width 

 of m^ 1'2. 



Typical localitv. Sebha. 



Type. Male. No. 66. Killed 19 May, 1901. 



This Ti'ipolitan representative of the qtcadrimacidattcs-gron-p is 

 readily distinguishable fi'om its Egyptian allies by its larger bullae 

 and bi'ighter and more unifonn ochraceous buffy colour. No 

 members of the gi'oup have been recorded from Algeria. 



10. Merioxes shawi Rozet. 



2. Tarhuna. 6/4/1. 



4. 5. 7. 11. W. Nefed. 14-15/4/1. 



146.150. Elcusher. 24/7/1. 



152-153. 156. 157. 158. W. Aggar. 25-26/7/1. 



162. Bou Cheifa. 2/8/1. 



In spite of the large number of localities at which one or other 

 of the two species were taken, it is noticeable that at no single 

 place did Mr. Dodson catch both M. shawl and 31. schoiisboei. 

 Perhaps they will prove to be mutually exclusive, as they are so 



