NO. I BLACK FLIES OF GUATEMALA — DALMAT 149 



tenna 330 ju, long, 4-segmented, yellow, far surpassing the basal stalk 

 of the cephalic fan ; segment i <3<2> i ; clear area between segments 

 2 and 3 ; no transverse striations. Submentum with 9 apical teeth, 

 shaped like half of a hexagon, all of approximately the same length ; 

 ventrolateral row composed of 3 to 5 hairs in a straight row, the apical 

 three bifid at their ends, the basal hairs simple ; lateral margin of sub- 

 mentum with 4 toothlike processes, two of them near the apical teeth, 

 the other two more basal. Occipital cleft dome-shaped, the apex 

 pointed (pi. 42, fig. 404). 



Thorax and Abdomen: Pseudopod (thoracic proleg) with 34 

 rows of hooks at its apex ; postclypeal sclerites rarely visible. Poste- 

 rior sucker with 78-82 rows of hooks. Anal gills with 3 fleshy main 

 divisions, at times each of these with i to 3 fingerlike projections. 

 Anterior and posterior arms of X-shaped sclerite well sclerotized; 

 anterior arms with wedge-shaped membranous expansion on the outer 

 margin, the arms extending only slightly beyond these ; posterior arms 

 rather long; no rectal scales. Two rather small ventral papillae on 

 eighth segment, no plaques. 



Types.— ^ (U.S.N.M. No. 15414) in the collection of the United 

 States National Museum; collected in Santa Lucrecia, Veracruz, 

 Mexico. 



SIMULIUM (LANEA) JACOBSI Dalmat 



Simiilhtm (Lanea) jacobsi Dalmat, Ann. Ent. Soc. Amer., vol. 46, No. i, pp. 

 40-42, figs. 9-11, 1953 (original description, larva). 



In giving the original description of this species, the author men- 

 tioned his desire to find further examples so that the adult and pupa 

 could be described. Unfortunately, sufficient opportunity to collect 

 in the same locality did not arise and the description of the larva is 

 all that is available at present. It is hoped that future workers will 

 have the opportunity to make further collections of this species. 



Larva (pi. 40, fig. 368, and pi. 42, fig. 405). — Total length, 4.6 mm. 

 Length of head capsule i.i times its width. Width of thorax 1.4 

 times that of head. First 4 abdominal segments 1.3 times width of 

 head ; segments 5-7 expanded, greatest width at segment 6 which is 

 about 1.4 times that of segments 1-4; segment 8 sharply tapering. 

 General color white, with transverse purple bands across posterior 

 half of abdominal segments 1-8, these interrupted on segments 5-7 by 

 longitudinal white lines that cross through the transverse bands giving 

 a striped appearance to that region of the abdomen ; without dark 

 patches on the ventrolateral regions of segments 6 and 7. 



Head: Frons-clypeus (pi. 40, fig. 368) pale yellow with a very 



