MAY FLIES AND jMTDGES OF NEW YORK 163 



jointed, the last joint elongated. Antennae of the male 10- 

 jointed, the first joint thick and disk-like, the following eight egg- 

 shaped, the last one thicker and longer than the others, all with 

 long hairs, the last one verticillate; antennae of the female 

 6-joiuted. the first one thick and disk-like, the following four 

 ellipsoidal, the last one somewhat elongate, all with short 

 hairs. Eves round, ocelli wanting. Mesothorax greatly arched, 

 prolonged over the head, witliout transverse suture; scutellum 

 small; metathorax much arched. The 8-jointed abdomen is 

 narrow and long. Legs elongated; slender; the posterior pair 

 of tibiae somewhat thickened, spurred; metatarsi elongated; 

 claws and pulvilli very small. Wings in outline club-shaped, 

 bare, and bent down; anal angle wanting; anterior margin 

 thickened. Halteres free; venation as shown on pl.36, fig.7. 

 Genitalia of male shown on pl.32, fig.4 (after Kieffer). Antennae 

 of male 11-jointed according to Kieffer (1899). 



Of the larvae and pupae of the memibers of this genus, but one 

 species has been described as far as I am aware; i. e. Cory- 

 n o n e u r a 1 e m n a e Frauenfeld (1866) . (ri.BG, figs. 1 to 5.) 

 He describes the larvae as filiform, thickened anteriorly, white, 

 with distinct incisures (flg.l). The chitinous i»ale broAvn head 

 is oval, with two black eye spots. The antennae 3-jointed 1.5 

 times as long as the head. The first thoracic segment is in the 

 form of a truncated cone, upon the ventral side of Avhich is a 

 cephalad projecting process, with a bilobed extremity, each lobe 

 possessing a crown of delicate setae. The next thoracic seganent 

 largest, with two oval, stigma-like spots on each side. The fol- 

 lowing 8 gradually decreasing in size ; the last is nearly cylindri- 

 cal, and has upon the dorsal surface a prominence upon which 

 there are several upright setae. There are two anal blood gills 

 and tAvo prominent anal prolegs, at the extremity of each of the 

 latter there is a circle of curved setae. Length 3.7 mm. 



The pupa is described as being smooth and pale yellow^ in color; 

 the A\ ing sheaths being one third of the entire length. The ab- 

 dominal segments are distinct; the anal end is blunt, upon each 

 side with a hyaline crescent-shaped disk, each Avith 8 long setae 

 upon its margin (fig.4 and 5). Length 1.2 num. The imago 

 resembles C. s c u t e 1 1 a t a AVinn. (an European species) . 



