AQUATIC INSECTS IN NEW YORK STATE 331 



11 Thorax enlarged; abdomen usually with 



long hairs; usually a complex respira- 

 tory apparatus at the anal end Culicidae 



Body much elongated (12) 



12 Last segment of the abdomen with two 



fleshy points Rhyphidae 



Last segment tapering, often with a few 

 long hairs. Body snakelike, segments of 

 nearly uniform length. (Oeratopogon) Chironomidae 



13 With anal prolegs and blood gills. (Chi- 



ronomus, Tanypus, etc.) Chironomidae 



Without anal prolegs; a broad abdomen, 

 with a terminal sucker; head with a 

 pair of fanlike organs (black flies) Simuliidae 



14 With rudimentary mouth parts; body with 



13 segments; peripneustic (i. e. spiracles 



on the median segments). Gall gnats. ., Cecidomyiidae 



With biting jaws. Head incomplete, 

 small, retractile, not containing nerve 

 ganglia; 12 body segments; posterior 

 stigmata usually with some fleshy fila- 

 ments (crane flies) Tipulidae 



Pupae 



1 Prothoracic spiracles, if present, borne on 



appendages (Nematocera) (2) 



Prothoracic spiracles sessile Brachycera 



2 Nonaquatic. Leaf miners or gall makers 



(Cecidomyiidae); larvae living in fungi 

 (Mycetophilidae); larvae living in the 

 earth (Bibionidae); larvae living under 

 bark (some Ceratopogon) 

 Aquatic or semiaquatic (3) 



3 Pupae in a fibrous cocoon (4) 



Without cocoon, sometimes in the old lar- 

 val tube (5) 



4 Cocoon cornucopialike, the coarse thoracic 



filaments of the pupa projecting. These 



filaments are usually few in number Simuliidae 



Thoracic filaments of the pupa if present, 

 entirely within the cocoon, the latter 

 usually subcylindric Some Chironomidae 



5 Body convex, hard shelled, and attached 



limpetlike to the rock (6) 



Not attached nor limpetlike (7) 



6 Shield-shaped, flattened. Thoracic breath- 



ing tubes are subcylindrici Some Psychodidae 



ISee Professor Kellogg's paper in Ent. News, Feb. 1901. 



