1SOMBTBUS. 47 



J with well-marked secondary sexual characters. Tail ex- 

 ceedingly long, eight times as long as carapace ; 1st caudal segment 

 more than twice as long as wide, 4th about one and a half times 

 as long as carapace and five times as long as wide. Chelw also 

 very long and slender ; hand (fig. 12, B) slender, parallel-sided, 

 not wider than brachium, its width about one-third the length of 

 the underhand, which is at least two-thirds the length of the 

 movable finger. 



Measurements in mm. (specimens from Bombay). 5 . Total 

 length 49. carapace 5, tail 23, underhand 2-5, movable finger 6. 

 tf . Total length 62, carapace 5, tail 42, underhand 4'5, movable 

 finger 7. 



Loc. Introduced in connection with shipping from the Oriental 

 Region all over the tropical and subtropical parts of Asia, Africa, 

 and America. So far as British India is concerned, the species 

 has been found in Bombay, Kanichi, Ceylon (Trincomali and 

 Peradeuiya), Burma (Rangoon, Akyab, &c.), and the Andaman 

 Islands. 



The wide distribution and sexual variability of this species 

 account, to a great extent, for its long list of synonyms. 



33. Isometrus thurstoni, Pocock, Jour. Bom. N. It. Soc. vii, p. 297, 

 1893 ; Kraep. Tierr., Scorp. etc. p. 67, 1899. 



Allied to the preceding. 



. Coloured very much as in /. europieus, but the yellow tri- 

 angle in 1'rout of the ocular tubercle reduced to a small spot, which 

 is slightly broader behind than in front and does not quite reach 

 the anterior margin : the ground-colour of the body and its 

 appendages is darker, the median longitudinal band on the terga 

 more conspicuous, whereas the tail, legs, and chelae are not so 

 variegated, being of a more uniform yellowish-brown tint. Struc- 

 turally the $ much resembles that of /. europceus, but the vesicle 

 is very noticeably stouter; the spine smaller and farther re- 

 moved from the base of the aculeus. Hand larger than in /. euro- 

 pceus, as wide as brachium ; length of underhand at least half 

 that of movable digit. Pectinal teeth 14-16. 



cJ . Differing from <S of /. europceus in the same characters of 

 colour and form of vesicle as the $ , and sexually modified in much 

 the same way, with tail and chelae long. The tail, however, is 

 not so long as in /. europceus, about 7| times as long as the 

 carapace ; 4th segment not four times as long as wide. Chelae 

 differing from those of I. europwus in having the brachium only 

 about four times as long as wide, the hand (fig. 12, C) inflated, 

 much wider than the brachium, its width at least half the length 

 of the underhand, and the immovable finger sinuous in the proximal 

 half, so that when closed the two are not in contact at base. 



Measurements in mm. of c? (type) from Shevaroy Hills. Total 

 length 67, carapace 6, tail 45, underhand 5, width of hand 2-5. 



