ISOBtEIBUS. 51 



basal portion, and base or digits infuscate ; legs externally varie- 

 gated. Upper side of body closely and entirely covered with 

 larger and smaller granules ; a row of coarser granules along 

 posterior border of terga ; last st< mum closely granular throughout, 

 and furnished with four granular keel-:. Tail slender, about four 

 times as long as carapace, closely granular, normally keeled; 

 median lateral keel present only on 1st segment , merely represented 

 on tlie 2nd posteriorly by about three granules; vesicle smooth, 

 long, about twice as long as aculeus ; spine large, triangularly 

 pointed, its inferior edge continuous with the corresponding edge 

 of the vesicle, its upper edge furnished with a pair of tubercles; 

 distance between spine and base of aculeus scarcely equal to diameter 

 of base of aculeus; aculeus moderately long. CTielce with humerus 

 and brachium granular and normally keeled : brachium wide, only 

 twice as long as wide, and furnished in front with about half-a- 

 dozen denticles; hand large, wider than brachium, smooth, not 

 .crested; lingers short, in contact, movable only slightly longer 

 than underhand, furnished with 7 rows of teeth. Pectinal teeth 

 12-13. 'J'ar.si furnished below with a few setae, arranged in two 

 rows. 



Mrirsii '.,•<■ 1 1 tents in mm. — Total length 23, tail 13, carapace '■'>. 



Lor. Madras (Henderson). 



A single female example. 



39. Isometrus acanthums, Pocock, Jour. Bum. N. 11. .Sue xii, p. 264, 

 L899. 



d . Allied to the preceding species, and most nearly resembling 

 J. basilicus in colour. Carapace lined with black ; anteocular 

 region black, with a few small yellow spots ; terga with six rellow 

 and live black longitudinal bands ; 4th and 5th sternal plaits lined 

 with black ; tail delicately lined with black ; chelae and legs yellow 

 spotted with black, black on brachium predominating and circum- 

 scribing definite yellow spots ; hand almost entirely vellow, not 

 black at base of lingers ; fingers not black, but yellow aud spotted 

 with black. Upper side of trunk granular, and crested as in 

 the preceding species; carapaa as long as the 2nd caudal segment ; 

 5th abdominal sternum marked with tour complete and equal 

 granular keels. Tail long and slender, about seven limes the 

 length of the carapace; keels stronger than in /. Imsilicus, and the 

 terminal granule on the superior keels on 2nd and 3rd segments 

 long, erect, and spiniform; vesicle with coarsely granular crests 

 below ; spine not so thick as in the preceding species, triangular, 

 but with blunt, not rounded or sharp apex, armed with only two 

 denticles ; aculeus short and curved. Ch<l<> much as in I . basilicus, 

 but the front of the brachium normally crested and subdenticulate, 

 not furnished with a few large teeth; baud smooth, wider (ban 

 brachium, its width about half the Length of the underhand; m ivable 

 digit as long a> underhand, not so long a< carapace, furnished w ith 

 7 rows of teeth. P, iti„ at teeth 16. 



e2 



