NO. I BLACK FLIES OF GUATEMALA — DALMAT 223 



Abdomen : Tergite of segment i dark brown, with short black 

 hairs ; pleurites dark brown with long black hairs that reach segment 3. 

 Segment 2 with its anterior half brown, the posterior half black, the 

 posterior half and sides white-pruinose. All other segments velvety 

 dark brown, the posterior halves appearing almost black ; lateral re- 

 gions of these segments white-pruinose ; short black hairs on all seg- 

 ments, longer ones on segments 7 and 8. Sternites tan. 



Genitalia: Height of cercus (pi. 32, fig. 202) about three and 

 one-half times its length (width), the posterior angles well rounded. 

 Anal lobe (pi. 32, fig. 202) triangular in shape, narrow at its dorsal 

 extremity, very wide (long) ventrally where the posterior angle ex- 

 tends under the cercus. Genital rod (pi. 32, fig. 204) usually without 

 basal dilatation, at most with very slight broadening ; arms of genital 

 fork ribbonlike, twisted, with i or 2 somewhat sclerotized triangular 

 extensions near the midregion. Ovipositor (pi. 32, fig. 203) small, 

 triangular in shape, the height equal to the base. 



Pupa (pi. 37, fig. 304, and pi. 39, fig, 344). — Granulosity over 

 entire thorax, more pronounced in central region ; 3 trifid and i simple 

 trichome on either side of midline. Dorsal surface of abdominal seg- 

 ments : No granulosity ; spines on segments 2-4 are anteriorly di- 

 rected, those on segments 6-9 are posteriorly directed ; segment 2 

 with 8 simple spines in transverse row three-fourths the distance from 

 the anterior margin, the row divided by median space ; anterior to the 

 outermost spine on each extremity are 2 similar spines ; segments 3 

 and 4 each with 8 simple spines in transverse row three- fourths the 

 distance from the anterior margin, the row divided by median space ; 

 segment 6 with 5-12 (usually 8-10) simple spines in irregular trans- 

 verse row behind the anterior margin, without median separation, and 

 with comblike groups of spines lateral to both ends of the row ; seg- 

 ment 7 with 10-12 simple spines in transverse row across the anterior 

 margin, the row divided in two by median separation, and with combs 

 lateral to each end; segment 8 with 11-13 simple spines in transverse 

 row across anterior margin, without median separation, and with 

 combs lateral to both ends ; segment 9 with 8 spines in transverse row 

 across anterior margin, divided by median space, without combs. 

 Ventral surface of abdominal segments : No granulosity ; all spines 

 are anteriorly directed ; segment 4 with 4 simple spines in transverse 

 row across posterior margin, the row divided in two by median sepa- 

 ration ; segment 5 with 4 bifid teeth in transverse row somewhat before 

 the posterior margin, with median separation ; segments 6 and 7 with 

 4 spines in transverse row somewhat before the posterior margin, the 

 outer teeth simple, the inner one bifid ; the two spines on either side of 



