NO. I BLACK FLIES OF GUATEMALA — DALMAT I99 



of head ; abdominal segments 5-7 somewhat expanded, 1,3 times width 

 of segments 1-4; in profile, the larva appears like others in subgenus 

 Dyarella, with the posterior end narrowing rapidly. General color 

 yellow to tan, without dark patches on ventrolateral areas of segments 

 6 and 7. 



Head : Patterns on frons-clypeus and epicranial plates best demon- 

 strated on plate 41, figure 2)7^- Each cephalic fan with approximately 

 56 pectinate branches ; hairs on these very short and close together, 

 with longer, stouter hairs, simple or bifid, at regular intervals. Mandi- 

 ble with 2 teeth on its inner margin, appearing to arise from a single 

 base, the most distal better developed. Antenna 440 /x long, yellow, 

 4-segmented, easily surpassing the basal stalk of the cephalic fan; 

 segment 2>i>3; segment 2 with 2 clear regions in which there are 

 superficial indentations making the segment appear like three indi- 

 vidual segments ; segment i with longitudinal striations. Submentum 

 with 9 apical teeth, the central one and two outer ones longer than the 

 others ; all teeth triangular in shape, pointed ; ventrolateral row com- 

 posed of 9-10 hairs in straight line, the apical five trifid, next three 

 bifid, and basal hair simple ; lateral margin of submentum with 6 

 toothlike indentations near apex. Occipital cleft pointed (pi. 42, fig. 



413)- 



Thorax and Abdomen : Pseudopod (thoracic proleg) with 56-58 



rows of hooks on its apex; postclypeal sclerites small, but well 

 sclerotized and separated, one at each posterior junction of the frons- 

 clypeus and epicranial plate. Posterior sucker with 220-230 rows of 

 hooks. Anal gills with 3 fleshy, bulbous branches, each with 12 short 

 fingerlike projections that are close together. The X-shaped sclerite 

 is simple, both anterior and posterior arms well sclerotized ; posterior 

 arms rather long, reaching a distance down on either side of the larva; 

 no pigmented patches, rectal scales or spines. No ventral papillae or 

 plaques on eighth segment. 



Types.— Tv^o $$ (U.S.N.M. No. 191 12), collection of the United 

 States National Museum ; one collected in Cordoba, Mexico, De- 

 cember 17, 1907, the other in Las Vegas Hot Springs, N. Mex., 

 U. S. A., August 7. 



SIMULITJM (DYARELLA) SMARTI Vargas 



Sttnulhitn (Eusimulium) smarti Vargas, Puerto Rico Journ. Publ. Health Trop. 



Med., vol. 21, pp. 327-33'^ (English) or 332-335 (Spanish), figs. 1-5, 1946 



(original description, (^, ?, and pupa). 

 Simulium {Dyarella) smarti Vargas, Vargas, Martinez, and Diaz, Rev. 



Inst. Salubr. Enferm. Trop., vol. 7, No. 3, p. 180, figs. 140 and 159, 1946 



