320 NEW YORK STATE MUSEUM 



ChironoTnus decorus 



7 Mandible of larva. xl50 



8 Labium of larva. xlOO 

 n Pupa. xG 



10 Ventral aspect of labrum of larva: an, anterior comb; c, posterior 



comb; Ir, lateral arm. xlSO 



11 Dorsal aspect of second abdominal segment of pupa. x40 



12 Anal end of pupa. x40 



13 Labium of larva (of another variety or possil)ly species). xl80 



Chironomus (?) plumosus 



14 Spur of the lateral fin of eighth segment of pupa. xlOO 



15 Labium of larva. xl80 



16 Maxilla of larva : p, palpus. xlSO 



PLATE 24 

 Cricotopus exilis 



1 A^entral aspect of mouth parts of larva : 1, labium ; mx, maxilla : p» 



palpus; by, hypopharynx. x250 



2 A^entral aspect of the labrum. x250 



3 Caudal end of pupa. xOO 



4 Mandible of larva. x250 



Cricotopus trifasciatus 



5 Ventral aspect of mouth parts of larva, laliium and maxilla. xl50 



6 Mandible of larva. xl50 



7 Lateral aspect of abdominal segments of pupa. x35 



8 Respiratory organ of pupa. xl.50 



9 Lateral hair-tuft of larva. xl50 



10 Caudal end of pupa with the caudal end )f enclosed imago. x35 



Orthocladius flavus 



11 Hypopharynx of larva. x80 



12 Ventral aspect of mouth parts of larva: a, antenna; md, mandible j 



mx, maxilla ; p, palpus ; 1, labium. x80 



13 Respiratory organ of pupa. x60 



14 Ventral aspect of labrum of larva : la, lateral arm. x250 



15 Lateral aspect of the posterior end of the seventh abdominal segment 



of the pupa 



16 Caudal end of pupa. x25 



17 Larval case, natural size 



Orthocladius nivoriundus 



18 Venti-al aspect of labrum of larva : la, lateral arm. xl50 



19 Antenna of larva. x150 



20 Mandible of larva. xl50 



21 Ventral aspect of mouth parts of larva : 1, labium ; mx, maxilla ; hy^ 



hypopharynx. xl50 



22 Dorsal aspect of abdominal segment of pupa. xSO 



23 Respiratory organ of pupa. x60 



24 Caudal appendage of pupa. x35 



