360 Mr. R. I. Pocock on Scorpiones and 



Specimens obtained in the forest at Santarein and at 

 Pavintins under leaves and rotten wood. 



The type of this s]iecies was obtained by H. W. Bates 

 at Altar do Chao, Santarem. 



Order SCORPIONES. 



Family ButhidsB. 



Genus IsOMETRUS, Hempr. & Ehrenb. 



Isometrus macnlatus (De Geer). 



A specimen of this ubiquitous species was taken on the 

 vessel at Para. 



Genus TiTYUS, C. Koch. 

 Tityus Camhridgei, sp. n. (Figs. 1, 1 a, p. 362.) 



? . — Colour of upperside a uniform black or reddish black 

 throughout, paler below ; pectines testaceous ; a triangular 

 smooth testaceous area on the middle of the hinder border of 

 the third sternite. 



Sculjituring, granulation, t^c. as in the Bogotd form 

 forcipula, Gcrvais { = a7)iericanus, Thorell, Kraepelin, &c.), 

 but not so coarse. 



Tail parallel-sided, segments 2 and 4 of equal width, the 

 fourth twice as long as wide ; the inferior crests on segments 

 2-4 not confluent, the median lateral crest of the second 

 only visible on the posterior fourth of the segment, or, at 

 most, represented in front by minute granules; tail about 5^ 

 times the length of the carapace; the hand and digit a little 

 less in length than the first two segments and half the third, 

 and twice the length of the carapace ; width of the fourth 

 segment equal to half its length, width of the fifth a little less 

 than half its length. 



Hand as wide as the brachium, the latter only a little 

 longer than the carapace and less than three times as long as 

 broad; hand-back two thirds the length of the carapace and 

 half the length of tiie movable digit, which has 15 rows of 

 teeth. 



Pectinal teeth 22 ; base of shaft lobate. 



cJ. — Tail feebly incrassate posteriorly as in the female, 

 about 6^ times the length of the carapace ; the finger and 

 hand as long as its first two segments and half the third, and 

 2^ times the length of the carapace ; filth caudal segment 

 nearly three times as long as wide. 



Chela long and slender. Carapace about | the length of 



