426 PROCEEDINGS OF THE XATTOXAL MUSEUM vol. loe 



shown in figure 6,e, although the shape of the parameres, if correct, 

 is very unusual. 



In addition to the female holotype there is one female paratype. 



Formicaphagus bolivianus, new species 



Figures 4,d; 5,e 



Type: Female adult from Myrmotherula axillaris fresnayana 

 (d'Orbigny), collected by the author at Santa Ana, Rio Coroico, 

 Bolivia, July 26, 1934 (author's collection). 



Diagnosis: A medium sized species with head as wide as long 

 (0.445) and somewhat triangular in shape; the preantennal margin 

 irregular in outline (fig. 4,(1); frons very narrow, with scarcely any 

 median depression; anterior plate small, with sides swollen latterly 

 at tips of premarginal carinae and vnth. less than half its length 

 exposed. Premarginal carinae and nodi wide and strongly pigmented; 

 the inner carinae supportmg the anterior plate narrow, but incrassa- 

 tions quite large; coni very small, with greater portion under head; 

 eye very minute (shown too large in figure); postmarginal carinae 

 present but poorly pigmented. 



Pro thorax rather large (0.13 X 0.26), with slightly convex sides; 

 pterothorax small (0.22 X 0.37), with lateral and posterior margins 

 perfectly straight. Abdomen normal, with rather narrow pleurites, 

 pitchy black above, brown and slightly wider below; dorsal "heads" 

 short and bluntly pointed, ventral "heads" much longer and paler; 

 genital sternite rather small and well pigmented but sternites IV 

 and V almost invisible; posterior margin of genital plate an open 

 V-shape, with short, thick setae; the setae of ventral patches on 

 each side of segment VIII unusually abundant, there being eight in 

 the longitudinal row and a cluster of four in anterior portion of 

 segment, all of which are short and most point towards the rear in 

 the holotype, but in the female paratype they are as shown in figure 

 5,e, being longer than in the type specimen. 



Formicaphagus grallariae, new species 



Figures 3,b; 5,/; 6,/ 



Types: Male and female adults from Grallaria perspicillata inter- 

 media Ridgway, collected by the author at El Hogar, Costa Rica, 

 Aug. 28, 1906 (author's collection) . 



DiAGXosis: A species of medium size, with head slightly longer 

 than wide in both sexes, and with female not much larger than male. 

 The entii-e body is clear, pale brown, the abdomen slightly paler, 

 with tergites and sternites clearly defined. 



The head, back of coni, has a rather squarish appearance but from 

 the coni the sides converge sharply in a straight line to tips of frons, 



