some South- American AviculariiclEe. 89 



the groove and proximally passing into stout spines ; on the 

 anterior side of the trochanter there are a few longish spines 

 and some thinner plumose bristles. 



Sternum Yery conwex, both longitudinally and transversely, 

 the middle of its surface projecting considerably below the 

 level of the lower side of the coxae. 



Measurements in millimetres. — Total length 38 ; carapace 

 i7"5 ; first leg 47, second 42, third 39, fourth 51 ; patella + 

 tibia of first 17'5, of fourth 17 ; protarsus + tarsus of fourth 21, 

 of first 16. 



Loc. Tucuman, 450 m. in the Argentine. 



This species differs from all known to me in the strong and 

 extraordinary convexity of its sternum. Apart from this 

 feature it would fall alongside A. Brocklehursti in the sub- 

 joined table, but differs in other respects from that species. 



The females of the species of the genus known to me may 

 be diagnosed as follows : — 



a. Sternum quite flat, higher than inferior surface 

 of coxse. 

 a^. Patella, tibia, and protarsus of legs with 

 broad pale distal band ; anterior side of 

 femur of first leg and posterior side of 

 femur of palp with feathery scopula ex- 

 tending nearly to distal end of segment . . fjeniculata, C. K. 

 b^. Patella, tibia, and protarsus of legs with at 

 most a narrow distal band; anterior side 

 of femur of first leg and posterior side of 

 femur of palp without feathery scopula or 

 scopulate only at base. 

 «-. Anterior side of first le^ studded at 

 base with plumose hairs in addition to 

 those constitutLng the stridiilating-appa- 

 ratus. 

 a^. No plumose bristles on posterior side of 

 coxa and femur of palp ; anterior 

 median eyes less than a diameter from 

 each other and from the laterals ; legs 



longer Brocklehursti, F. Cb. 



¥. Some plumose bristles present upon the 

 posterior side of the coxa and femur of 

 palp ; anterior median eyes more than 

 a diameter from each other and from 



the laterals ; legs shorter tarda, sp. n. 



b'^. Anterior side of first leg without plumose 



hairs, apart from those forming the stri- 



dulating-organ. 



a*. Legs longer, fourth about three times as 



long as carapace, which is only as long 



as its femur and half the patella, &c. . . antillensis, sp. n, 



b*. Legs shorter, ibui'th about two and a 



