260 



HABITS OF IMAGINES 



The imagines have much the same habits as Mycetophihdae, but 

 I have rarely seen them feign death as do the imagines of Cordyla and 

 Mycetophila. Bngnoriste, which has a very long proboscis, is com- 

 monly found on flowers of Brigeron and similar plants. Most species 

 of Sciara are common on plants and assumably feed on nectar. 



Family MACROCBRIDAB 



I have not found the early stages of any species of this family, 

 and consequently can not include it in my keys to the larvae and pu- 

 pae. 



The species are generally rare in North America, but in Europe 

 several occur rather commonly, especially under overhanging banks 

 of streams in or near woods. In early spring they may be beaten from 

 such banks, where grass or ferns overhang their edges, and from the 

 fact that I have taken some species very late in the fall and again early 

 in the spring I assume that they hibernate in the adult stage. 



There is but one genus in the family, twelve species of which are 

 listed bv Johannsen. Three species are known to occur in Illinois. 



Family PLATYURIDAB 



FAMII^Y CHARACTERS 



Larva. — Head subquadrate, the labrum slightly protruded; an- 

 tennae very short ; mandibles serrate ; maxillary palpi sessile ; maxillae 

 serrate ; median dorsal sclerite of head not tapering to a point poste- 

 riorly. Thorax and abdomen without distinguishable spiracles, the 

 latter with a pair of protrusive blood-gills on apical segment ; all seg- 

 ments with a number of flat transverse ridges separated by rather 

 deep and very narrow depressions; entire body slightly flattened and 

 with a narrow lateral extension each side which is crossed by ridges 

 as is the dorsum. 



Pupa. — Head more protruded than in Mycetophihdae; antennae 

 broad, projecting upward and backward in a straight line, ending 

 near base of wing. Abdominal spiracles elevated; legs long, the 

 apices of hind pair extending to apex of abdomen. 



HABITS OF LARVAE 



The larvae live in slimy webs on fungi, usually on the under sur- 

 face of such as grow upon fallen or decaying timber. They move 



