MAY FLIES AND MIDGES OF NEW YORK 87 



KEYS TO GENERA OF THE CHIRONOMIDAE 



Larvae 



a Abdomen with prominent rounded elevations or cushions, with rows of 

 teeth on the inferior (anterior) angles of the segments 



13. Psamathiomyia 

 'hi Ahdominal segments without these cushions 



I) Aquatic footless snake-like larva, or terrestrial larva with thoracic 

 and anal feet, and many setae and bristles on body segments, pi. 17, 



figs. 1 and 4 ( Group Ceratopogon) 



M) Not as above 



c With retractile antennae, the latter often quite long, long stilt-like 

 legs, the caudal tufts of hair mounted on cylindrical processes, 



pl.19, lig.9 ( Group T any pus) 



cc Not with all the above characters 



(I With the two caudal hair tufts mounted on cylindrical projec- 

 tions 



r With six seta-like processes on each of the caudal projections, 

 three long and three short. Eyes prominent, round, on ante- 

 rior angles of the head, pi. 34, figs. 21, 22, 23 (European) 



26. W u 1 p i e 1 1 a 

 - - Eyes not on anterior angles of head 



f With blood gills on venter of eleventh segment 



31. Hydrobaenus 

 ff With blood gills only at end of twelfth segment 



44. Metriocneruus 

 dd Caudal tufts on small rounded papillae 



e Antennae elongate, at least one half and often as long or longer 



than the head ; compare also pi. 20, fig.10 

 f With two anal blood gills, pl.36, figs. 1, 2, 3 



25. C o r y B o n e u r a ( 1 e m n a ) 



ff With four anal blood gills ; antennae mounted on basal promi- 

 nence, pi. 26, figs. 5, 8 42. Tanytarsus 



ee Antennae short 



f Larvae usually blood red ; eleventh body segment with two 

 pairs of blood gills, pi. 15, fig.4. .38. C h i r o n o m u s (pt.) 

 ff Larvae greenish, yellowish, or whitish 



g The maxiliary palpus usually noticeably longer than broad. 

 Larva in pools, pond water, or slow streams, pi. 23, figs. 3 



and 1(5 38. Chironomus (pt. ) 



//.'/ I 'a I pus a I out as long as broad, pl.24, figs. 5, 12, 20 



/; Full-grown larva not over G mm. long, green or bluish- 

 green in color. Anterior abdominal segments of greater 

 diameter than the posterior ones. Mandibles often 

 transversely wrinkled; the anterior prolegs usually with 

 pectinate setae 



s 



f 39. C r i c o t o p u s 

 \ 41. O r t h o c 1 a d i u 



