Scorpions of the ^enw5 Tityus. 517 



the length of the second ; hand 

 narrower, its width at most equal 

 to the length from the eye to the 

 posterior margin of the carapace ; 



digits less strongly sinuate metuendus, Poc. 



b^. Tail slender, feebly incrassate, width 

 of fourth segment less than half its 

 length ; width of hand equal to width 

 of brachium, less than that of vesicle, 

 and about one third the length of 

 the hand-back ; digits contiguous . . Camhridgei, Poc. 

 b. Inferior keels on the third and fourth (some- 

 times also on the second) caudal segments 

 united to form a single median keel. 

 a'. Tail short, about six times the length of 

 the carapace, which is about equal to the 

 length of the third caudal segment ; bra- 

 chium less than three times as long as 

 wide, the width of the hand about half the 

 length of the movable digit ; sterna and 

 intercaiiual spaces of tail much smoother ; 

 a median keel on the posterior third of 

 the third caudal segment and on the pos- 

 terior half of the fourth magnunanus, sp. n. 



i'. Tail long, more than seven times the 

 length of the carapace, which is much 

 shorter than its third segment ; hand and 

 brachium narrower, the former more than 

 three times as long as broad, the latter 

 about one third the length of the movable 

 digit in width ; sterna and intercarinal 

 spaces more coarsely granular. 

 a'. Inferior crests on the second caudal seg- 

 ment not united posteriorly, those of the 

 third united in the posterior half of the 

 segment and those of the fourth in the 

 posterior three fourths of the segment. . trinitatis, sp. n. 

 A*. Inferior crests on the second caudal seg- 

 ment united in the posterior third of its 

 length, of the third in the posterior two 

 thirds, and of the fourth in the poste- 

 rior five sixths androcottoides, Karsch. 



Females. 



a. Caudal segments 1 to 4 with a pair of parallel 



granular keels. 



a}. Vesicle punctured and smooth below; (hand 



obsoletely keeled, wider than vesicle ; a 



strong terminal denticle on the upper 



crest of caudal segments 2 to 4 ; pectinal 



teeth 15-17) macrochirus, sp. n. 



6'. Vesicle serially granular below. 



(i^. Vesicle large, its width very noticeably 

 greater than that of the brachium and 

 hand ; spine close to base of aculeus 

 (tail incrassate, very coarsely granular, 



