MAY PLIES AND MIDGES OF NEW YORK 87 



KEYS TO GENERA OF THE CHIRONOMIDAE 



Larvae 



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

 teeth on the inferior (anterior) angles of the segments 



13. Psamathiomyia 

 aa Abdominal segments without these cushions 



b A<iuatic 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 Geratopogon) 



&b 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.l9, flg.9 (Group Tan yp us) 



cc Not with all the above characters 



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

 tions 

 e 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, pl.34, figs. 21, 22, 23 (European) 



26. W^ u 1 p i e 11 a 

 ee Eyes not on anterior angles of head 



f With blood gills on venter of eleventh segment 



31. H y d r b a e n u s 

 ff With blood gills only at end of twelfth segment 



44. Metriocnemus 

 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 pl.20, fig.lO 

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



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

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

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



ee Antennae short 



/ Larvae usually blood red; eleventh body segment with two 

 pairs of blood gills, pl.l5, fig.4. .38. Chironomus (pt.) 

 ff Larvae greenish, yellowish, or whitish 



g The maxillary palpus usually noticeably longer than broad. 

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



and 16 38. Chironomus (pt.) 



gg Palpus about as long as broad, pl.24, figs. 5, 12, 20 



h Full-grown larva not over 6 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 J 39. C r i c o t o p u s 



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



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