296 The Forms of Jaculus jaculus in Egypt and Syria. 
Jaculus jaculus butleri, subsp. n. 
Size and essential characters as in J.J. jaculus, but the 
colour above nearly “ avellaneous,” as compared with 
“pinkish buffy ” in that animal. Proximal whitish band on 
tail, that just before the subterminal black ring, practically 
never running through the black ring below to join the white 
terminal pencil, as it so very frequently does in jaculus. 
Dimensions of the type (from dry skin) :— 
Head and body 115 mm.; tail 196 ; 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 
number 192. Collected in the winter of 1908, and presented 
by A. L. Butler, Esq., to whom we owe nearly all of our fine 
series of twenty-five specimens. 
It is interesting to notice how very sharp the dividing-line 
between jaculus and butleri is. Specimens from Dongola 
(kerma and Merowe) are absolutely jaculus, while some 
from Shendi are distinctly budlert, of which we also have a 
specimen from Sennaar. Then, but little further south, there 
occurs gordont, with an incisor-bulla length of upwards of 
35 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 schliitert. General colour above pale drab, 
the fine blackish tips to the hairs unusually distinct, and, on 
the sides, showing particularly strongly on the otherwise 
white hairs, these lateral hairs in jacudus being, like those of 
the back, more or less buffy. Tail light-coloured, its sub- 
terminal dark brown ring completely separating the white 
terminal tuft from the rest of the tail. 
Size of skull and inflation of the bulle about at the maxi- 
mum found in jaculus. 
