from the Lower Amazons &c. 85 



Protarsus iv. bent suddenly in the middle in a sinuous 

 form, the basal angle armed with 5 spines and a stout curved 

 chisel-headed spur beneath the joint, its apex directed 

 outwards. Eye-formula similar to others of the genus. 

 Tarsal claws 2, with 4 sinuous denticules ; claw-tuft present. 



Pedipalp. Tibia with a stout black spur on the outer side 

 at apex; palpal organs (PL III. fig. vi. e). The form of the 

 tibial spur is very variable. 



2 . — Structure similar to that of male. Carapace in profile 

 less concave and gibbous at base. Cephalic area slightly 

 gibbous. Protarsus iv. normal. Vulva (PI. III. fig. iv. d). 

 Fang-groove with 5 denticules on lower margin, 3 on upper. 



Measurements in millim. — $ . Tot. len. 22, carap. 10 ; legs 

 i. 38, iv. 41 -o; pat.+tib. i. 13, iv. 13, iii. 10. 



This species, remarkable amongst other allied forms in the 

 male sex for the curious development of the posterior pro- 

 tarsus, which is developed in somewhat the same manner as 

 the protarsus of the first pair of legs in some of the Thera- 

 phosidaj, was taken at La Palma (Costa Rica) by Mr. J. F. 

 Tristram. There were in the collection two adult males, one 

 adult female, and several immature of the latter sex. 



Ctenus rectipes, sp. n., (J . 



Hab. Iguarassu, Brazil. 



Type in coll. Brit. Mus. Nat. Hist. London. 



Total length 17 mm., carapace 8'5; legs i. 35, iv. 39; 

 carapace equals pat. + tib. iii. in length; pat. + tib. i. longer 

 than pat. + tib. iv. 



Colour. Carapace, legs, sternum, and mouth-parts ma- 

 hogany-brown, clothed with yellow-grey pubescence. Abdo- 

 men unicolorous above, clutiied with fine rufous-yellow hairs. 

 Ventral area dark sooty brown, with a narrow, central, lanceo- 

 late pale band extending from the genital rima almost to the 

 spinners. 



Structure. Carapace raised, gibbous, and slightly bilobate 

 behind. Other general characters similar to those of others 

 of the group. Tib. i. and ii. with 5 — 5 spines beneath, 2 

 lateral and 2 dorsal. Protarsus iv. straight. Tibia of pedi- 

 palp longer than broad, with a short straight apophysis, 

 obliquely truncate at apex, directed forwards from the apex 

 of the joint on outer side, its outer surface striate and its 

 length less than broadest diameter of the joint. Tarsal 

 claws 2. 



Eyes. Second row straight by anterior margins ; ocular 

 quadrangle as broad as, or slightly broader than, long, a little 



