318 NEW YORK STATE MUSEUM 



Diamesa waltlii 

 9 Ventral aspect of the head : md, mandible ; mx, maxilla ; p, palpus ; 

 ulr, labrum ; la, lateral arms ; 1, labium ; by, bypopbarynx 



Chironomus sens. lat. sp. 

 10 Dorsal aspect of bead: ds, dorsal sclerite ; a, antenna (wanting); 

 b, frontal process 



PLATE 21 

 Chironomus tenellus 



1 Ventral aspect of bead of larva : ulr, labrum ; la, lateral arms ; md, 



mandible ; mx, maxilla ; p, palpus ; 1, labium. xl50 



2 Caudal end of pupa. xGO 



3 Lateral aspect of the fifth abdominal segment of pupa. x60 



4 Antenna of larva. xl50 



Chironomus nigricans 



5 Antenna of larva. xloO ■ 



G Ventral aspect of bead of larva : 1, labium ; by, bypopbarynx ; mx, 

 maxilla; imx, inner lobe of maxilla; p, palpus. xl50 



7 Mandible of larva. xl50 



8 Anterior prolegs of larva. x25 



9 Posterior end of larva. x25 



10 Epipbarynx of larva : an, anterior comb ; c, posterior comb. x250 



11 Dorsal aspect of second and third abdominal segments of pupa. x25 



12 Comb at caudal end of lateral fin of eightli segment of pupa. x60 



Chironomus flavicingula 



13 Ventral aspect of epipbarynx of larva, distended : f, posterior comb ; 



s, curved setae. x250 



14 Ventral aspect of labrum: a, epipbarynx (shown enlarged in fig.l3). 



xl50 



15 Dorsal aspect of labrum. x250 



16 Dorsal aspect of third segment of pupa. x25 



17 Lateral fin of eighth segment of pupa. x60 



18 Labium of larva. xl50 



19 Ventral aspect of mouth parts of larva : 1, labium ; mx, maxilla ; p, 



palpus ; by, bypopbarynx 



PLATE 22 

 Chironomus fiavus 



1 Ventral aspect of head of larva : a, antenna ; md, mandible ; mx, 



maxilla ; p, palpus ; by, bypopbarynx ; 1, labium ; f, fan-membrane. 

 xl50 



2 Caudal end of larva : a, caudal setae ; b, blood gills. x35 



3 Lateral aspect of second and third abdominal segments of pupa. x35 



4 Spur of lateral fin of eighth segment of pupa. xGO 



Tanytarsus deflectus 

 G Respiratory organ of pupa. xlOO 



Chironomus sp. (SI) 

 7 Venti'al aspect of mouth parts, labium and maxilla. xlOO 



