483 



Frontal tubercles absent. Pronotum of moderate width, extend- 

 ing nearly to upper margin of mesonotum. Legs slender; fore tarsi 

 with basal joint nearly twice as long as fore tibiae (57:29), second 

 joint a fourth longer than third (25 : 20). Third vein ends but little 

 farther in front of apex of wing than fourth does behind it ; cross 

 vein slightly in front of wing-middle; fork of cubitus almost at 

 middle of wing. 



Length, 3 mm. 



Tvpe locality, Urbana, 111., Julv 6, 19 14, at light (C. A. Hart 

 and J. R. ALalloch). 



Early stages and male unknown. 



66. Chironomus digitatus, n. sp. 



Larza. — Length, 9-10 mm. Blood-red. Head slightly longer 

 than broad ; antenna short and inconspicuous, generally widely di- 

 vergent and at almost right angles to the long axis of head, apical 

 jointed portion missing from type; maxillary palpi about as long as 

 antennae and projecting similarly; lateral arm of labrum as in Fig- 

 ure 8, Plate XX HI ; labium w^ith the middle third pale yellow, the 

 third on each side dark brown-black, shape as in Figure 13, Plate 

 XXX; mandibles as in Figure 12. Anterior pseudopods as in other 

 species of CJiirononuis, the posterior pair with apical claws; dorsal 

 respiratorv organs present; eleventh segment without ventral respir- 

 atorv organs ; dorsal papillae short, with about twelve sensory hairs. 



Pupa. — Length, 10 mm. Reddish brown. Frontal tubercles 

 acute and of moderate size, similar to that shown in Figure i, Plate 

 XXXI ; thoracic respiratory organs ending in many white hairlike 

 filaments ; immediately posterior to base of respiratory organs is an 

 elongated protuberance, w4iich is but slightly tapering apically and 

 three times as long as its basal diameter; posterior to the foregoing 

 and a short distance in front of base of wing is a short diagonal 

 ridge, which has at its lower, anterior extremity a blunt tubercle 

 slightly longer than its basal diameter, and at its upper, posterior 

 extremity a similar, much shorter, wartlike tubercle ; disc of thorax 

 with a few weak hairs and closely placed scalelike setulai. On mid- 

 dle of first abdominal segment is a transverse row of short brown 

 thorns similar to that shown in Figure 9, Plate XXXI, surface of 

 all segments finely honeycombed (Fig. 15, a) ; segments 2-7 with 

 a preapical strip of setula; (Fig. 15, /;, c, d) which become less curved 

 and weaker successively towards seventh segment ; second segment 

 with the normal apical transverse row of blackish brown setulse, the 

 row widely interrupted mcdianly (Fig. 9) ; lateral margins of seg- 



