Pedipalpi Jrom the Lower Amazons. 361 



the brachium, which is at least four times as long as broad ; 

 hand long and slender, externally concave, its width equal 

 to that of the brachium and about one third the length of 

 the hand-back, which is a little less than the length of the 

 carapace and more than half the length of the movable digit ; 

 digits in contact only feebly lobate basally. 



'Pectinal teeth 21-22. 



Measurements in milHmetres. — ? . Total length 72 ; length 

 of carapace 7'8, of tail 43, length of its fourth segment 7"0, 

 width 3"8 ; widtli of vesicle 2'8, of brachium and hand 2*8 ; 

 length of brachium 8'5, of hand-back 5, of movable digit 10'2. 



cJ. Total length 80; length of carapace 7-6, of tail 62^ 

 length of fourth segment 9*5, width i^^[) ; width of vesicle 3, 

 of brachium and liand 2*5; length of brachium 11, of hand- 

 back 7, of movable digit 1 2. 



Loc. Para (type, two males and a female). 



Apart from finer granulation &c., this_ species may be 

 distinguished from T. forcipula, Gervais, by the following 

 features : — 



In the female of forcipula (co-typical example) the tail is 

 very distinctly incrassate, the fourth and fifth segments being 

 distinctly wider than the first, and their width about | their 

 length ; the crests are much stronger and the median lateral 

 on the second is complete, though weaker forwards. Still 

 more striking are the differential characters of the male : as I 

 have already ])ointed out (Ann. &. Mag. Nat. Hist., June 

 1889, pp. 54-56), the male oiforcipuki has the tail of normal 

 length, but enormously thickened posteriorly, the width of 

 the fourth segment being almost equal to its length ; again, 

 the chelee are not elongate, but the hand is enormously 

 thickened, nearly twice the width of the brachium, the digits 

 being widely separated, sinuate and lobate. 



In its sexual features Camhridcjei resembles and rocotto ides 

 of Karscli, but, apart from the differential feature [)reseiitcd 

 by the distinctness of the ioiferior caudal keels, the hand of 

 tfie male has a different form, as also has the vesicle of the 

 tail. 



Tityus metuendus^ sp. n. (Figs. 2, 2 a, p. 302.) 



? . — Very like tliat of T. Camhridijei, but the tail thicker, 

 the width of the fourth segment considerably more than half 

 its length; the granulations of the tail also much less distinct. 



hand distinctly wider than the brachium and much less 

 strongly crested than in Cambrrdgei. 



Pectinal teeth 19. 



