NO. I BLACK FLIES OF GUATEMALA DALMAT 79 



2. Dorsum of first two abdominal segments covered with granulosity and with 

 transverse row of simple spines ; dorsum of segments 3 and 4 with more 

 than 8 spines in transverse row; 3 or 7 hairs on either side of ventral sur- 

 face of ninth abdominal segment, of which no more than i is bifid ; terminal 



spines cone-shaped Gigantodax Enderlein, 1925 



Dorsum of first two abdominal segments with or without granulosity, without 

 transverse row of simple spines ; dorsum of segments 3 and 4 with only 8 

 spines in transverse row; 5 hairs on either side of ventral surface of ninth 

 abdominal segment, of which 2 are bifid (C. aguirrei Dalmat and C. pacheco- 

 lunai (De Leon)) or i trifid (C roblesi (De Leon)) ; terminal spines tubu- 

 lar or fingerlike in appearance Cnephia Enderlein, 1921 



SPECIES OF THE GENUS CNEPHIA, BASED ON PUPAL CHARACTERS 



1. Respiratory apparatus of each side composed of only two tubular filaments, 



each tapering toward apex ; ventral surfaces of segments ^-7 each with 

 transverse row of 10 simple spines ; cocoon covering only posterior half 



of abdomen aguirrei Dalmat 



Respiratory apparatus of each side composed of more than two branches ; 

 ventral surfaces of segments 2>-7 with, at most, 4 simple spines in trans- 

 verse row ; cocoon covering all of abdomen and approximately one-fourth 

 of thorax 2 



2. Respiratory apparatus composed of 12-13 filaments, each tapering from its 



base to apex ; thorax and dorsum of abdomen covered with granulosity ; 



terminal spines approximately 0.15 mm. long pacheco-lunai (De Leon) 



Respiratory apparatus of each side composed of 4 saclike trunks, two thin fila- 

 ments extending from the apex of each of three of the trunks, and one fila- 

 ment from the fourth ; thorax and abdomen without granulosity ; terminal 

 spines approximately 0.06 mm. long roblesi (De Leon) 



SPECIES OF THE GENUS GIGANTODAX, BASED ON PUPAL CHARACTERS 



Respiratory apparatus of each side composed of 9 somewhat flattened branches, 

 each ovoid in cross section and spatulate at the apex ; dorsal surface of each of 

 abdominal segments 6-8 with single transverse row of at most 30 spines ; ven- 

 tral surface of segments 5-7 each with row of 6 spines ; three simple hairs on 

 either side of ventral surface of ninth abdominal segment; cocoon covering 

 abdomen and three-fourths of thorax utighti Vargas, Martinez, and Diaz 



Respiratory apparatus of each side divided into 13-15 tubular branches, each 

 tapering toward its apex and several with elongate filaments extending from 

 their extremities ; dorsal surface of each of abdominal segments 6-8 with trans- 

 verse row of at least 40 spines, segment 8 also with second row of 6 heavier 

 spines ; ventral surfaces of segments 5 and 6 each with row of 8 spines, that of 

 segment 7 with row of 4 spines ; i bifid and 6 simple hairs on either side of 

 ventral surface of ninth abdominal segment; cocoon covering three- fourths of 

 abdomen only aqnamarensis (De Leon) 



SUBGENERA OF THE GENUS SIMULIUM, BASED ON PUPAL CHARACTERS 



I. Transverse row of heavy spines on dorsal surface of segments 2-4 only 2 



Transverse row of heavy spines on other segments in addition to 2-4 3 



