NO. I BLACK FLIES OF GUATEMALA DALMAT 93 



base; ventrolateral row with three hairs in straight line, the most- 

 distal hair bifid near the apex, the other two simple ; lateral margin 

 of submentum with 6 toothlike serrations. Occipital cleft very shallow, 

 dome-shaped (pi. 42, fig. 393). 



Thorax and Abdomen : Pseudopod (thoracic proleg) with 22-26 

 rows of hooks on its apex ; postclypeal sclerites well developed, long, 

 wider at outer end, gradually narrowing toward inner end, almost 

 meeting at midline ; not heavily pigmented. Posterior sucker with 

 72-75 rows of hooks. Anal gills three in number, very broad at the 

 base, tapered toward apex. Anterior arms of X-shaped sclerite short, 

 not very heavily sclerotized ; posterior arms well sclerotized, extending 

 only to lateral margins of segment; small membranous connection 

 between the two anterior arms, near their origin ; no rectal scales but 

 with a few bifid and trifid scales between the anterior and posterior 

 arm of each side. Segment 8 with two ventral papillae, appearing like 

 short but broad-based cones, translucent ; no sclerotized plaques. 



Types. — Holotype (5)> 6 slides, and allotype {(^ dissected from 

 pupal case), 5 slides, in collection of the United States National Mu- 

 seum, Holotype collected in the Rio San Diego, Finca San Diego, 

 Acatenango, Chimaltenango, Guatemala, October 30, 1947; allotype 

 collected in the Rio Reposadera, Finca San Vicente Pacun, Acate- 

 nango, July 14, 1948. Metatype (5), in collection of Herbert T. 

 Dalmat, collected September 24, 1947. The J* J*, $?, larvae, and pupae 

 used for the above description were collected from the Rio Socorro, 

 Acatenango, Chimaltenango, Guatemala. 



CNEPHIA PACHECO-LUNAI (De Leon) 



Simulium pachcco-lunai De Leon, BoI. Sanit. Guatemala, vol. 52, pp. 67-68, fig. 3, 



1944 (original description, pupal respiratory filament). 

 Cnephia pacheco-lunai (DeLeon), Dalmat, Ann. Ent. Soc. Amer., vol. 44, 



No. I, p. 48, 1 95 1 (distinguishing characters of <S, ?, and pupa). 



Male (pi. 22, figs. 4-6). — (First description of male.) 3.9 mm. long. 



Head: Holoptic. Eyes shiny dark brown. Antenna 650 fx long, 

 1 1 -segmented, slightly tapering; segment 3 very long; segment 

 3=1-1-2, 3>4-f5, 3>ii ; scape and pedicel light brown, the flagellum 

 dark brown to black. Palpi black. Clypeus dark brown, with numerous 

 long black hairs along lateral margins. 



Thorax : Mesonotum velvety black, when viewed at certain angles, 

 the entire scutum may appear gray to white-pruinose ; very long, nar- 

 row, yellow, scalelike hairs densely covering entire mesonotum ; short, 

 fine, black hairs also over entire surface, long black ones in prescutellar 

 region. Humeral angles brown, with yellow scalelike hairs and with 



