296 The Forms </ Jaculus jaculus in Etjypt and Syria. 



Jaculus jaculus butleri, subsp. n. 



Size and essential charactors as in J.j.jaciilus, but tlic 

 colour above nearly " avellaneous/' as compared with 

 " pinkish bufTy " in that animal. Proximal whitish band on 

 tail, that just before the subterminal black rin<^, practically 

 never running through the black ring below to join the white 

 terminal pencil, as it so very frequently does m jaculus. 



Dimensions of the type (from dry skin) : — 



Head and body 115 mm.; tail 11)6 ; hind foot 61. 



Skull : incisor-bulla length 33*2 ; condylo-incisive length 

 28*7 ; width between outer corners of anteorbital foramina 

 16'2 ; bimeatal width 23'3 ; length of bulla 12*8 ; upper 

 molar series 5. 



Hab. Khartoum and neighbouring localities. Type from 

 Khartoum. 



Type. Adult female. B.M. no. 11. 11, 25. 80. Original 

 luimbL'r 192. Collected in the winter of 1908, and presented 

 by A. L. Butler, Esq., to Avhom we owe nearly all of our fine 

 series of twenty-tive specimens. 



It is interesting to notice how very sharp the dividing-line 

 between jacuhcs and butleri is. Specimens from Dongola 

 (Kerma and Merowe) are absolutely jaculus, while some 

 from Shendi are distinctly butleri, of which we also have a 

 specimen from Sennaar. Then, but little further south, there 

 occurs gordo7ii, with an incisor-bulla length of upwards of 

 '65 mm. 



At the northern end of the J. jaculus area another form 

 deserves a technical name : — 



Jaculus jaculus syrius, subsp. n. 



Size as in true Egyptian jaculus, not larger and with 

 longer limbs as in the geographically intermediate form from 

 Jaffa described as schVuteri. General colour above pale drab, 

 the fine blackish tips to the hairs unusually distinct, and, on 

 the sides, showing paiticularly strongly on the otherwise 

 white hairs, these lateral hairs in jaculus being, like those of 

 the back, more or less buflfy. Tail light-coloured, its sub- 

 terminal dark brown ring completely separating the white 

 terminal tuft fiom tiie rest of the tail. 



Size of skull and inflation of the bullae about at the maxi- 

 mum found in jaculus. 



