some South- American Aviculaiiidse. 101 



strongly pvocurved, the anterior edge of the medians being a 

 little behind the centre of the laterals, nearly evenly spaced 

 and a little unequal in size, the medians being the larger and 

 separated from each other by a space which equals their 

 diameter ; posterior medians much smaller than the anterior 

 medians, but not very widely separated from them, closer to 

 the posterior laterals^ which are about as large as the anterior 

 laterals, and separated from them by a space which is quite 

 equal to the long diameter of the latter *. 



Legs long and slender, 1 and 4, 2, 3; tarsi of fourth longer 

 than of first, patella and tibia of first considerably longer than 

 of fourth : 2^^'otarsal scopula of first covering three-quarters 

 of the segment, with a pair of long spines at its base; that of 

 the second covering two thirds, with three to five long spines 

 at its base; that of the third covering half the segment, with 

 many basal spines ; that of the fourth covering about one 

 fifth of the segment, which is elsewhere strongly spined : 

 tiln'ce of all the legs and of the palpus spined ; an anterior 

 spine on the patella of first and second legs. 



Spurs on the first tibia well developed, the upper stout, 

 straight, cylindrical, blunt, and bearing a long sinuous spine 

 on its underside, the lower crescentically cylindrical, curved, 

 with a stout spine on its apex ; the proiarsus distinctly but 

 slightly-bowed at its proximal end. 



The palpal organ piriform, terminating in a delicate hair-like 

 process ; at the base of the narrower portion the organ offers 

 a spiral twist ; there are externally two keels, the lower of 

 which is very conspicuous. 



Stridulating-organ consisting of a large cluster of fine close- 

 set bristles clothing the distal third of the posterior surface of 

 the coxa of the palp, and of two smaller clusters of similar 

 close-set bristles at the distal end of the anterior surface of 

 the coxa of the first leg, one just above and the other just 

 below the suture. 



? (not quite mature). — Carapace like that of the male, but 

 a little Avider in proportion to its length, especially the cephalic 

 region, mandibles wider at the base ; length of carapace equal 

 to that of patella and tibia of fourth leg and exceeding the 

 protarsus, its width exceeding the patella and tibia of the 

 third leg. Eyes as in the male described. 



* One male example from the same bottle, and unmistakably belonging 

 to the same species, which has been dried, has the anterior median eyes 

 much smaller, being smaller than the anterior lateral and separated by a 

 space which considerably exceeds a diameter. This circumstance shows 

 how very careful one should be in tiie use of ocular characters for the 

 distinction of genera and species. 



