HADRURUS. 



7 



G> 



looking Wood's statement on this point. Hence it seems likely that the smoothness 



- 



of the organ referred to may be a sign of immaturity or characteristic of the female. 



The pectinal teeth in H. hirsutus vary from 25 to 40, the usual number bein 

 about 32-35. 



The characters of H. hirsutus given in the synoptical table are taken from the adult 



r \ 



'I 



example from San Bernardino, which, from the size of the pectines, I regard as a 

 male. For a similar reason the type of II aztecus is assigned to that sex. 



The San Bernardino example gives the following measurements: — Total length 

 97 mm., carapace 11*5, tail 63 ; width of vesicle 6, of brachium 4, of hand 5 ; length of 





finger 12 # 5. The pectines surpass the end of the coxa of the fourth leg when lying at 

 rest, and bear 34-35 teeth. A smaller specimen, with the pectines falling short of the 

 end of the coxa of the fourth leg and bearing 32 teeth, measures as follows : — Total 



length 75 mm., carapace 9*5, tail 64 ; width of brachium 3'2, of hand 4*2 ; length of 

 movable finger 10. 



It is noticeable that the hand in the San Bernardino example is much narrower than 



■ 



in the type of //. aztecus. 



2. Hadrurus aztecus, sp. n. (Tab. II. figg. 1, 1 a-f 9 s .) 



2 . Colour : upperside of trunk a rich reddish-brown, part of carapace and tail much paler ; chelae and legs clear 

 ochre-yellow. Carapace as long as fifth caudal segment and as the first caudal segment, and more than 

 half the second ; the frontal area sparsely but coarsely granular ; posterior and lateral portions much more 

 thickly granular. Terga granular posteriorly and laterally, the anterior nearly smooth in the middle, the 

 last granular throughout, with median crest. Sterna coriaceous, the last smooth and keelless on the middle, 

 granular laterally, with a series of granules forming a single crest on each side. Tail nearly five times as long 

 as the carapace, the fifth segment very slightly more than twice as long as wide, the first as long as wide ; 

 a few granules on the upperside of the segments ; the lower side of segments 1-3 smooth, with smooth 

 keels, those on the third only weakly granular posteriorly, on the fourth more strongly granular ; superior 

 and superior lateral keels granular ; a median lateral keel, anteriorly abbreviated on segments 2-4, 

 present on segments 1-4 ; fifth segment with superior crests strongly granular ; the three inferior crests 

 strong and denticulate, the intervening area coarsely but not closely granular ; vesicle large, as wide as 

 high, its width equal to that of the- fifth segment and to half the length of the carapace, sparsely granular 

 below and bristly, narrower than hand. Chelce bristly; humerus with granular crests, and a few granules 

 in front, elsewhere smooth ; brachium with granular crests and a few granules above distally, elsewhere 

 smooth or nearly so and polished j hand wide, polished and smooth except for a granular crest on its 

 inner edge and one above the underhand, its width equal to the length of the underhand, more than half 

 the length of the carapace, and far exceeding the width of the brachium ; movable finger almost as long 

 as carapace, about twice the length of the underhand, not lobate, and furnished with eight rows of teeth. 

 Legs smooth, except the femora, which are finely granular externally and denticulate below ; protarsus 

 furnished externally with a comb of fine spicules. Pectinal teeth 35-37. 



Measurements in mm. — Total length 103 ; carapace 13 ; tail 63, width of first segment 7, of fifth 6 ; height 



of vesicle 5*5, width 6 ; length of brachium 10-5, width 4 ; width of hand 7 ; length of underhand 6-5, 



of movable finger 12*5. 



u 



Had. Mexico, Jalapa (Mus. Brit.). 



