NO. I BLACK FLIES OF GUATEMALA — DALMAT I29 



shape, the apical angle strongly tapered, the other two angles blunt ; 

 inner basal angle hyaline, outer angle, which emerges at about the 

 middle of the expansion, somewhat sclerotized. Ovipositor (pi. 29, 

 fig. 143) small, elongate, the apex somewhat expanded. 



Pupa (pi, 2,^, fig. 284, and pi. 39, fig. 324) . — Granulosity on central 

 part of thorax; 4 arborescent trichomes on either side of midline. 

 Dorsal surface of abdominal segments: No granulosity; spines on 

 segments 2-4 are anteriorly directed, those on segments 7-9 are pos- 

 teriorly directed ; segment 2 with 8 simple, hairlike spines in transverse 

 row, crossing the segment about three-fourths the distance from an- 

 terior margin, the row divided in two by a median space ; anterior to 

 the outermost spine on either side of the row are 2 hairs, the most- 

 anterior heavier; segments 3 and 4 with 8 simple spines in a trans- 

 verse row across the middle of the segments, the row being divided 

 by median space ; segment 7 with 8 simple spines in transverse row on 

 anterior margin, with median separation, and with about 10 comblike 

 groups of spines lateral to each end of the row ; segment 8 with 19-24 

 simple spines in transverse row across anterior margin, with median 

 separation, and with combs lateral to both ends of the row ; segment 

 9 with what appears to be a band of posteriorly directed denticles 

 along the anterior margin, divided in two by a median space. Ventral 

 surface of abdominal segments : No granulosity ; all spines are an- 

 teriorly directed ; segment 4 with a single simple spine on either side 

 of the midline, about three-fourths the distance from the anterior 

 margin; segment 5 with transverse row of 4 bifid spines, crossing 

 about three- fourths the distance from the anterior margin, divided in 

 two by median space ; segments 6 and 7 with 4 spines in a transverse 

 row about three-fourths the distance from the anterior margin, the 

 outer spines simple, the inner spines bifid ; the two spines on either 

 side of the midline are more separated than those on segment 5, the 

 distance between them approximately equal to that of the median 

 space. Terminal spines very small, ending in point. 



Respiratory apparatus (pi. 36, fig. 284) of each side emerging just 

 behind the anterior margin of thorax ; composed of 8 filaments which 

 branch as follows : 3-3-2 ; all filaments curve in one direction to give 

 the effect of a fan ; with superficial annulations and with microscopic 

 spicules. Maximum length of filaments, 2.7 mm., about 0.65 times 

 the length of the cocoon ; diameter, 40-60 /x. 



Cocoon (pi. 39, fig. 324) : Length of base, 4.1 mm.; maximum 

 width, 2.0 mm.; maximum height, 1.5 mm. Cocoon wall-pocket type, 

 without collar ; texture of case parchmentlike, the threads visible ; rim 

 around anterior aperture thickened. Cocoon covering abdomen and 

 thorax ; attached along a little more than half its base. 



