I.YCHAS. 37 



finger-keel, a little narrower than brachium, width a little less 

 than length of underhand : digits in contact, not sinuate ; the 

 movable longer than carapace, at least twice the length of the 

 underhand, armed with 6 rows of teeth, the basal very long, extend- 

 ing over half the length of the finger; the outer row of teeth 

 9 (8-10) in number ; the inner row only 5, situated in the distal 

 half. Legs externally granular, with short tibial spurs. Pectinal 

 teeth about 21. 



6 with tail a little longer than in § and stouter, the 5th 

 segment and vesicle being scarcely granular and the former not 

 cariuate. Chela' with hand much inflated, considerably wider than 

 brachium ; the underhand more than half the length of the movable 

 digit, which is slightly sinuate and armed with a large tubercle 

 at the base ; immovable finger with its basal half strongly arched, 

 so that when closed at the tip a wide space is left between the 

 basal ends of the two fingers. 



Measurements in mm. — $ . Total length 58, carapace 6, tail 32, 

 underhand 3, movable finger (5-5, width of hand 2. d" . Total 

 length 53, carapace 6, tail 33, underhand 4, movable linger (>-5, 

 width of hand 3. 



Distribution. Occurring in abundance in both Upper and Lower 

 Burma and Tenasserim (Occtes Sf Feci), thence spreading eastwards 

 into China and Siara, and southwards over the islands of the Indo- 

 Malayan area as far as Flores. 



Soc. ent. Ital xxv, p. 367, 1894; Kraep. Tierr., Scarp, etc. p. 44, 



is; H") (Archisoi)H'tras) : weberi, Karsch, Berlin, ent. '/.cits, xxvi, 

 ]). 184, 1882 (Isometrus) ; Kraep. Jb. Hamb. iviss. Anst. viii, p. 221, 



1891 (Archisometrus) : mesor, Simon, Ann. Mus. Genova, xx, 

 p. 371, 1884 (Isometrus) : phipsoni, Oates, Jour. Bom. N. H. Soc. 

 iii, p. 248, figs, l, 2, 1888 (Isometrus). 



5 . Colour : trunk much more uniformly fuscous above than in 

 mucronatus, the terga, however, marked with a pair of circular 

 yellow spots near the middle, and one on the posterior lateral 

 angles; the last tergum mostly yellow, blackish only in front; 

 anterior four caudal segments yellowish red above, last segment 

 and vesicle blackish; chela' mostly yellow; the extremity of the 

 brachium, the hand, and the basal half of the fingers blackish ; 

 legs yellowish, or blackish with yellow tarsi. Carapace and terga & 

 little more coarsely granular than in L. mucronatus. Last sternum 

 with 4 granular keels ; 3rd with rounded punctured spot in the 

 middle of its hinder portion. Tail much longer and thinner, 

 about six times as long as the carapace ; 2nd segment more than 

 twice, 4th about three times as long as wide; keels stronger than 

 in mucronatus ; the inferior lateral edges of the 5th cariuate. 

 Chelai with hand granular and distinctly cariuate above, but 



