NO. I BLACK FLIES OF GUATEMALA — DALMAT 159 



median separation, and with several comblike groups of minute spines 

 lateral to both ends of the row ; segment 8 with uninterrupted row of 

 30 simple spines across the anterior margin and with numerous combs 

 lateral to both extremities. Ventral surface of abdominal segments: 

 No granulosity ; all spines are anteriorly directed ; segment 4 with a 

 single long, simple spine on either side of midline at middle of segment, 

 with separation between the spines of either side ; segment 5 with 

 transverse row of 4 bifid spines, with median separation, somewhat 

 in front of the posterior margin ; segments 6 and 7 each with trans- 

 verse row of 4 spines about three-fourths the distance from the an- 

 terior margin, with median separation, the outer spines simple, the 

 inner spines bifid ; the 2 spines on either side of the midline of seg- 

 ments 6 and 7 are more separated than those of segment 5, the distance 

 between them being approximately equal to that of the median space. 

 Terminal spines very small, ending in points. 



Respiratory apparatus (pi. 36, fig. 290) of each side arising in the 

 region of the humeral angles, just behind the anterior margin of the 

 thorax ; composed of 8 filaments which branch as follows : 3-3-2 ; 

 all filaments with well-marked superficial annulation, and with granu- 

 losity; no microscopic spicules. Maximum length, 1.8 mm., about 

 0.64 times the length of the cocoon ; average diameter, 24 ju,. 



Cocoon (pi. 39, fig. 330) : Length of base, 2.8 mm. ; maximum 

 width, 1.5 mm.; maximum height, 1.4 mm. Cocoon of wall-pocket 

 type, without collar ; no winglike extensions from lateral margins of 

 base ; rim around anterior aperture thickened ; texture of case parch- 

 mentlike, granular, threads not visible. Cocoon covering abdomen and 

 two-thirds of thorax ; attached along the posterior half of its base. 



Larva. — No specimens available. 



Types.— 2 (U.S.N.M. No. 15408), in collection of the United 

 States National Museum ; collected in Tampico, Tamaulipas, Mexico. 



SIMULIUM (LANEA) VERACRUZANUM Vargas, Martinez, and Diaz 



SimuHum (Lanea) veracrusanum Vargas, Martinez, and Diaz, Rev. Inst. 

 Salubr. Enferm. Trop., vol. 7, No. 3, pp. 133-136, 170, figs. 53-57 and 155, 

 1946 (original description, c?, ?, pupa, and larva). — Dalmat, Ann. Ent. 

 Soc. Amer., vol. 44, No. i, pp. 55-57, 1951 (presence and distribution in 

 Guatemala). 



Male (pi. 24, figs. 46-48). — 3.0 mm. long. 



Head : Holoptic. Eyes very dark reddish brown, almost black. 

 Antenna 440 ju, long, ii-segmented, black ; segment 3>i 4-2, 3>44-5> 

 3> II. Palpi black. Clypeus black, white-pruinose, irregularly covered 

 with long black hairs. 



