10 E. B. Williamson and J. H. Williamson 



9 (8'). Male appendage with only an angle on the inner edge at about two-sevenths 



the length; apex of dorsum of segment 10 slightly elevated in the middorsal 

 line and concave on either side of this and dorsal to the appendages; dorsum 

 of segments 8-10 black, 8 with about the basal third pale (yellow or blue) ; 



stigma reddish brown kahli 



9'. Male appendage with a flattened tongue-like blade or lobe on the inner edge 

 at about one-third the length ; apex of dorsum of segment 10 not elevated 

 but low and flat; dorsum of segments 8-10 dark but not all distinctly black, 

 the pale basal area on 8 reduced to less than one-third the segment 10. 



10 (9'). Stigma reddish brown; labrum very narrowly black edged; outer end of 



mesostigmal lamina ending in a laterally directed free, acute point solutus 



10'. Stigma black; labrum with more black than in solutus; mesostigmal lamina 

 not ending in a free, acute point 11. 



11 (10'). Labrum with less than the anterior half black fragilis 



11'. Labrum largely black _ minor 



12 (8'). Stigma reddish brown; outer end of mesostigmal lamina angular or a free 



point 13. 



12'. Stigma black; outer end of mesostigmal lamina scarcely or not elevated but 

 low and rounded; valvular styles at their origin proximal to the level of the 

 apex of 10 ; dorsum of 9 largely dull brown, shading imperceptibly into the 

 pale lateral basal area on either side _ fragilis 



13 (12). Dorsum 8-10 black; a large distinct pale lateral basal area on either side 



of 9 _ Icahli 



13'. Dorsum of 8-10 brown; pale, lateral basal areas on 9 reduced, more widely 

 separated by the dorsal brown, less sharply outlined solutus 



Descriptions of Species 



1. Perilestcs cornutus Selys 



Abdomen male 46-50.5; hind wing male 22.5-25; stigma front wing 

 male 1.20-1.47; stigma hind wing male 1.27-1.50; abdominal appendage 

 male 1.40; male anterior lamina from apex of sternum of segment 1 to 

 apex of the posterior process 2.1. 



Male. — Head similar to that of remotus; the labium with a brown area 

 on the suture between the mentum and submentum. 



Prothorax similar to that of remotus, the proepimeron dark to black 

 and this dark area extended broadly onto the proepisternum ; hind border 

 semicircular. 



Thorax similar to that of remotus, the dark colors possibly duller, dark 

 brown instead of black over much of the dark areas of the mesothorax; 

 the pale area of the metepisternum more nearly reaches the wing base 

 above. 



Mesostigmal lamina elevated from either extremity, in nearly straight 

 edges, to a low but distinct obtuse angle placed nearer the lower extremity. 



Coxae similar to those of remotus. Femora black, more or less pale 

 on the anterior face, especially just before the apex. Tibiae pale to ob- 

 scure, the first and second sometimes largely darker to black above, with 

 less dark beneath, the third with little or no dark. 



Venation as in remotus; stigma reddish brown. 



