108 NEW YORK STATE MUSEUM 



flattened at the other, the latter with a minute rectangular 

 bolster with knobbed corners. 



The larvae emerge in the course of four or five days; a slender, 

 white, snake-like creature, differing in no wise from the full 

 grown Ceratopogon larva excepting that it has a rela- 

 tively larger head ; the posterior end has the usual setae. None 

 were reared to maturity, hence no dissections could be made of 

 the head, nor were any pupae obtained. The imago has been 

 fully described by Loew (1861). 



Subgenus 3. Serromyia Megerle in litt. 



Meigen Syst. Besclir. 1:66. 1818; Prionomyia Stephens. Cat'l Brit. 

 Ins. 2,37. 1829; Ceratopogon pt. C. Meigen, Stephens, loc. cit. 



The name Serromyia was first published by Meigen as a 

 manuscript name of Megerle's for Ceratopogon femora- 

 t u s Fabr. Later, in 1829, Stephens places into the Prionom- 

 yia all of Meigen's Ceratopogon group C, the members 

 of which have the hind femora thickened, and spinose beneath. 

 According to both Skuse (1889) and Kieffer (1902), the genus 

 may be defined as follows: Wings bare, the crossvein-like R„ 

 present; hind femora thickened, and spinose beneath. Belongs 

 to the group Ceratopogon. Several North American species. 



Subgenus 4. Heteromyia Say 



Amer. Ent. 2 : 79. 1825 ; and Compl. Wr. 1. (=P a c h y 1 e p t u s Walker. 



Ins. Saunders Dipt. 42G. 1856.) 



Heteromyia may be considered as a subgenus of P a 1 - 



p o m y i a and defined thus : Wings bare, the vein R, present, 



crossvein-like (resembling pl.17, fig.lG) ; media simple; femora 



spinose beneath, fore femora thickened (pl.37, figs. 8 and 9) . Say's 



description is as follows : 



Artificial character. Antennae porrect, filiform, ll-joiuted, five 

 terminal joints elongated; palpi exserted, four-jointed; basal joint 

 shortest, a little contracted in the middle; ocelli none; eyes reni- 

 form; posterior feet much elongated, slender, and with a single 

 nail at the tip; anterior pair with somewhat elongated coxae, and 

 much dilated femora, armed with a series of short spines on the 

 anterior edge, on which the arcuated tibia closes. 



Natural character. Body moderately slender; head small, 

 rounded, flattened before; antennae in the middle of the face; first 



