NO, I BLACK FLIES OF GUATEMALA — DALMAT I55 



and with microscopic spicules. Maximum length, 1.9 mm., about 0.6 

 the length of the cocoon ; average diameter, 20 fi. 



Cocoon (pi. 39, fig. 329) : Length of base, 3.1 mm. ; maximum 

 width, 2.2 mm.; maximum height, 1.7 mm. Cocoon of wall-pocket 

 type, without collar ; texture of case parchmentlike in the matrix of 

 which are seen loose threads; rim around anterior aperture well 

 thickened ; cocoon with small, lateral, winglike expansions. Cocoon 

 covering abdomen and two-thirds of thorax ; attached along posterior 

 half of base. 



Larva (pi. 40, fig. 369, and pi. 42, fig. 406). — Total length, 5.0- 

 5.2 mm. Length of head capsule 1.2 times its width. Width of thorax 

 1.4 times that of head. First 4 abdominal segments i.i times width 

 of head; segments 5-7 expanded, greatest at segment 6 which is 1.7 

 times the width of abdominal segments 1-4; cross section and profile 

 like those of other species in the subgenus Lanea. General color 

 creamy white, with numerous greenish-yellow markings; abdominal 

 segments 1-4 each with a yellow transverse band ; segments 5-7 appear 

 all yellow ; dark-brown dorsolateral patches on segment 7, hardly 

 visible on segment 6, 



Head: Designs on frons-clypeus and epicranial plates shown on 

 plate 40, figure 369. Each cephalic fan with 37-39 pectinate branches, 

 the hairs on these branches fine, short, and close together, intermixed 

 at intervals with longer bifid hairs. Mandible with 2 rather slender, 

 long, pointed teeth on its inner margin, the teeth well separated, the 

 distal tooth about twice the length of the other. Antenna 340 /x, long, 

 4-segmented, light brown, just passing the basal stalk of the cephalic 

 fan ; segments i and 2 subequal, each shorter than segment 3 ; pale 

 band at base of segment 3 ; no transverse striations. Submentum with 

 9 triangularly shaped apical teeth, the central one longer than the 

 others ; ventrolateral row composed of 3 bifid or trifid hairs in straight 

 line ; lateral margin of submentum with 4 toothlike serrations, the most 

 apical two heavily sclerotized like the apical teeth. Occipital cleft 

 dome-shaped, broad, almost semicircular (pi. 42, fig. 406). 



Thorax and Abdomen : Pseudopod (thoracic proleg) with 34 

 rows of hooks at its apex ; postclypeal sclerites medium-sized, fairly 

 well pigmented. Posterior sucker with 73-75 rows of hooks. Anal 

 gills with 3 main divisions, each with 3-4 fingerlike projections ; one 

 projection in each group longer than the others, somewhat club-shaped. 

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

 anterior arms with wedge-shaped expansions along the outer margins 

 that almost reach the extremity of the arms ; large green patch in 

 front of the anterior arms and between them ; on either side, between 



