402 MB. E. I. POCOCK ON THE 



BRACHIStrOSTEENUS, gGB. nOV. 



Syn. Mecocentrus, Simon, Ann. Soc. Ent. Fr. (5) x. p. 393. 



Carapace longitudinally sulcate throughout, the sulcus passing 

 over the tubercle, the anterior border lightly convex ; the ocular 

 tubercle in the middle of the carapace ; lateral eyes three in 

 number, minute, contiguous, just above the lateral border. 

 The terminal fang of the movable digit of the chelicerae long, the 

 fang at its base very short. 



Palpi moderately strong ; the digits armed with several short, 

 oblique series of denticles, the posterior denticles of each series 

 enlarged to form an external series of larger denticles ; a corre- 

 sponding internal series of denticles alternating with the external 

 series. 



Tail moderately long ; the aculeus of the vesicle long, slender, 

 and lightly curved. 



Stiff mat a elongate. 



Sternum almost invisible, owing to its having taken up a 

 vertical position behind the coxse of the second pair of walking- 

 limbs, distinctly of the pentagonal type, much wider than long, 

 with its posterior border deeply emarginate. 



The genital operculum very large, in contact with the coxse of 

 the second pair of walking-legs, its two halves separate in both 

 sexes. 



Pectines long, the intermediate lamellse formed of two rows of 

 sclerites. 



Legs long, the terminal tarsal segment carinate above, shortly 

 hairy below. 



Type, B. Ehrenbergii (Gerv.). 



This genus is certainly synonymous with Simon's Mecocentrus 

 and possibly with Thorell's Telegonus. But I cannot bring 

 myself to believe that it is the same as Telegonus of C. Koch. 

 This genus Telegonus, which was renamed Mecocentrus by 

 Karsch * on the grounds of the preoccupation of the name em- 

 ployed by Koch, was based upon a species versicolor f, which at 

 least differs from JBracMstosternus in the extreme thickness of 

 its tail. A glance at the figure of T. versicolor shows that all 

 the anterior caudal segments are considerably wider than long,. 



* Zeit. Naturwissen. (3) v. p. 408 (1880). 

 t Die Arachniden, iii. p. 52, iag. 207 (1836). 



