NO. I BLACK FLIES OF GUATEMALA — DALMAT 253 



Submentum with 9 apical teeth, triangular in shape, the central one 

 and the outermost on either side longer than the others ; ventrolateral 

 row composed of 8-1 1 hairs in a straight line, the apical five bifid or 

 trifid, the others simple ; at times some of the hairs are deeply bifur- 

 cated, one of the branches subdividing ; lateral margin of submentum 

 with a single, poorly defined toothlike serration. Occipital cleft dome- 

 shaped, the apex somewhat pointed (pi. 43, fig. 425). 



Thorax and Abdomen: Pseudopod (thoracic proleg) with 45-46 

 rows of hooks at its apex ; postclypeal sclerites long, narrow, poorly 

 sclerotized, appearing to extend from the posterior junction of the 

 frons-clypeus with the epicranial plates. Posterior sucker with 196- 

 204 rows of hooks. Anal gills with 3 main divisions that are short and 

 fleshy ; each of the two outer divisions usually has i broad projection 

 and 8 more slender projections ; the median division usually has i 

 broad and 11 slender projections ; besides this more common arrange- 

 ment, giving a total of 30 branches, there are at times only 25 

 branches, eight from each lateral division and nine from the median 

 one; all projections are fingerlike in appearance. Anterior arms of 

 X-shaped sclerite well sclerotized and somewhat broad ; posterior arms 

 completely encircling the posterior sucker, well sclerotized, slender; 

 lateral to the union with the anterior arms, the posterior arms bear 

 large, heavily sclerotized, pigmented plates that are triangular in form 

 and erect, with the apex pointing dorsally ; at times, a few specimens 

 are found in which a larger ventrally directed plate may also be pres- 

 ent ; no spines between the pigmented plates and the anterior arms ; 

 rectal scales absent. No dark wide bands transversely crossing the 

 dorsal surface just anterior to the branchiae as there are in larvispino- 

 sum. No ventral papillae or plaques on eighth segment. 



Types. — Pupa and larvae, in the collection of J, Romeo de Leon ; 

 collected from the "Salto de Zunil," a waterfall near the town of Zunil, 

 Department of Quezaltenango, 1,900 meters above sea level. Nu- 

 merous specimens, collected in Guatemala by the present author, were 

 used for the above description. 



SIMULIUM (HEARLEA) DELATORREI Dalmat 



Simiilium (Dyarella) delatorrei Dalmat, Ann. Ent. Soc. Amer., vol. 43, No. i, 

 pp. 137-143, figs. 1-7, 1950(b) (original description, <?, ?, and pupa). 



Simulium (Hearlea) delatorrei Dalmat, Ann. Ent. Soc. Amer., vol. 44, No. i, 

 p. 53, 1951- 



Male (pi. 26, figs. 103-105). — 3.1 mm. long. 



Head: Holoptic. Eyes dark reddish brown, shiny. Antenna 510 ju, 

 long, 1 1 -segmented, very slightly tapering; segment 3 = 4 + 5 = 11 = 



