324 



plate simple in form (Fig. 13) ; hypopharynx as in Figure 16. Abdo- 

 men without surface hairs; two leglike organs with warty processes 

 near the posterior margin* of each segment on the ventral side; apical 

 segment with eight hairs, four on each side, the anterior two widely 

 separated, the apical two close together; within the apical third of the 

 last segment are two retractile organs (their apices unarmed with 

 claws) which greatly resemble the posterior pseudopods of other chi- 

 ronomid larvae. 



The pupal and adult stages are described on pages 219-221 of this 

 volume of this Bulletin (Article IV). 



Illinois localities : Algonquin and Havana. Larvae were obtained 

 in considerable numbers from Thompson's Lake, near Havana, at a 

 depth of eight and a half feet. These were successfully reared to the 

 adult stage, by the writer, in 2-dram vials, in a room of the State 

 Laboratory. The pupae were found floating in the Illinois River near 

 Havana. It was observed that pupae kept in vials in which there still 

 remained a little water did not entirely leave the water before emer- 

 gence of the adult, as do certain other species of this genus, but re- 

 mained with the apical half of the abdomen submerged. 



Originally described from Pennsylvania, and subsequently recorded 

 from New Jersey by Smith. 



10. Palpomyia slossox^ Coquillett 



Ceratopogon slossonce Coquillett, Jour. N. Y. Ent. Soc, Vol. 13, 1905, p. 61. 

 Palpomyia slossonce (Coquillett) Malloeh, Bull. 111. State Lab. Nat. Hist., Vol. 

 10, p. 224. 



Originally described from a female specimen obtained on Mt. 

 Washington, N. H., by J\lrs. A. T. Slosson. Not subsequently re- 

 corded. 



Heteromyia Say 



Differs from Palpomyia in having the fore femora thickened and 

 spinose ventrally, and the other femora without spines. From Bezzia 

 and Prohezda the genus is distinguished by having the second vein 

 present, and from Johannsenoniyia by the presence of femoral thorns. 

 Serromyia is distinguished from Heteromyia by the much thickened 

 and spinose hind femora. 



I give herewith a key to those species which have the wings un- 

 marked. 



*As these organs are also present on the last thoracic segment and absent from 

 the penultimate abdominal one, I may be mistaken in considering them as situated on 

 the posterior margin, though they so appear in the mounted specimens before me. 



