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American Midland Naturalist Monograph No. 3 



long as basistyle, densely setiferous ventrally, with a very large lateral hatchet- 

 shaped lobe projecting mesad, closely followed by a long slender subapical 

 projection, also directed mesad; claw (Ds-C) inconspicuous, inserted on this 

 latter structure slightly before apex. 



larva (Fig. 70). — Large larva. Head quadrate, concave anteriorly, 

 broader than long. Antenna about one-third as long as head, extending near 

 anterior margin of head, sparsely spined; antennal tuft represented by a single 

 hair on outer third. Mouth brushes formed of stout prehensile hairs, each 

 hooked at tip and with a row of comb-like teeth along the side. Head hairs: 

 Hair A single, branched distally; hair B single, branched distally, inserted near 

 anterior margin of clypeus, extending beyond anterior margin of head; hair C 

 short, branched distally; hair d long, single, inserted mesad and slightly anter- 

 ior to hair C, extending beyond anterior margin of head; sutural (e) and trans- 

 sutural (f) multiple; supraorbital branch:d distally. Comb of eighth segment 



Fig. 70. Larva of Psorophora horvardii Coquilleft. A, Terminal segments. 

 B, Pecten spine. C, Comb scale. D, Head. 



