476 



The hypopygium resembles that of modcstus in having the superior 

 process much dilated apically, though the inferior process is almost 

 identical with that of indistinctiis. 



Length, 3-4 mm. 



Type locality, St. Joseph, 111., May 3, 1914. 



This species may readily be separated from modcstus and its 

 allies by the characters mentioned above, and from the other species in 

 Subsection 2 by the furcate inferior hypopygial process. 



The early stages are unknown to me. 



— =«- 56. Chironomus modestus Say 



Chironomus modesUis Say, Jour. Acad. Nat. Sci. Phil., Vol. 3, 1823, p. 13, sj). 3. 



Larra. — Length, 6-7 mm. Yellowish. Antennae slender, basal 

 joint distinctly longer than the apical four joints together, second joint 

 as long as third and fourth ; labium with middle tooth undivided and 

 distinctly stouter than the first lateral; mandibles of the usual form, 

 with three teeth on ventral surface in addition to the long apical tooth. 



Pupa. — Length 5-5.5 mm. Green. Thoracic respiratory organs 

 terminating in the usual white hairlike filaments. Second abdominal 

 segment with the normal apical transverse row of setulse, the posterior 

 two thirds of the surface with numerous short setulse which do not 

 extend to the lateral margins apically and gradually recede from them 

 towards base of segment; segments 3-6 with a similar discal patch, 

 enclosed in which are several rather indistinct rounded bare spots, and 

 in addition to the large patch and between it and bases of these seg- 

 ments there are two transversely elongate groups of setulse which in 

 some specimens unite on median line, forming a complete transverse 

 bar (PI. XXXI, Fig. 10) ; apical lateral process of eighth segment as 

 in Figure 17, Plate XXXI. 



Imago; Male. — Grass-green, slightly shining. Head yellowish 

 green ; scape of antennse yellow, flagellum fuscous, the plumes brown- 

 ish. Mesonotum with pale reddish or yellowish vittse ; sternopleura, 

 mesopleura, and postnotum largely reddish or reddish yellow. Abdo- 

 men bright green, rarely darkened apically. Legs greenish or yellow- 

 ish, fore knees, narrow apices of fore tibise, the whole of fore tarsi 

 from middle of the basal joint, and mid and hind tarsi from apex of 

 third joint to tips brown; mid and hind tibise with the normal black 

 apical comb. Wings clear, veins yellow. Halteres yellow, green api- 

 cally. 



Frontal tubercles indistinguishable. Pronotum rather broad, con- 

 tinued almost to upper margin of disc. Hypopygium as in Figure 8, 



