Scorpions from N. Somaliland. 179 



which I have subsequently seen the female examples obtained 

 by Dr. J. W. Gregory at Nclara and tlie Athi plains, but the 

 granulation of the trunk is altogether less coarse and the 

 structure of the tail is different. 



In the female of B. Emimi, and much more so in the male, 

 the segments are all higher and thicker, the height of the 

 fourth, for example, being equal to the length of the first and 

 to considerably more than half its own length, wliereas in 

 B. polystictus the height of the fourth is barely half its own 

 length and is distinctly less than the length of the first. 

 Again, in B. jwlystictus the upper surface of the segments is 

 much less strongly excavated and the superior keels are not 

 so high nor so coarsely granular, nor is the terminal granule 

 particularly prominent ; this is very noticeable in the fifth 

 segment, where the sides of the upper surface are convex 

 and distinctly higher throughout the length of the segment 

 than are the weakly granular side crests ; moreover, the length 

 of the fifth segment exceeds twice its width, which is not the 

 case in B. Eminii ; the vesicle, too, is larger and differently 

 shaped, its height being equal to its width and equal to the 

 width of the upper surface of the fifth, and is scarcely notice- 

 ably geniculate under the vesicle, which is only very slightly 

 curved. In Eminii, on the contrary, the height of the vesicle 

 is less than its width and less than, the width of the upper 

 surface of the fifth ; tlie vesicle is also strongly angled beneath 

 the aculeus, and the latter is strongly curved. 



In the chela? the hand is as wide as the forearm, the digits 

 are long, the movable twice the length of the hand-back and 

 furnished with 12 rows of teeth along the median series, the 

 basal row (composed of 19 denticles) being twice the length 

 of the others, which contain 8 to 10 denticles, and evidently 

 formed of two undivided shorter rows, as is shown by the 

 presence on each side of it of a tooth of the external series. 

 In B. Eminii there are 13 rows of median teeth, two corre- 

 sponding to the undivided basal series in polystictus ; but the 

 basal row is composed of 10 teeth, the one immediately in 

 front of it of 5, and the rest of from 6 to 8, almost always 

 7, and owing to the greater shortness of the digits the rows 

 are more crowded together. 



Pectinal teeth 18-19 and 20-20. 



Measurements in millimetres of type. — Total length 55 ; 

 length of carapace 6, of tail 31 ; width of first caudal seg- 

 ment 3-5, of fifth 2-8, length of latter Q>-6, height 2*8; length 

 of hand-back 3"5, of movable digit 7 ; width of hand 2'5. 



