269 



thoracic spiracles slightly elevated ; second annuhis of segment with 

 indications of a dorsal plate ; remaining thoracic and abdominal seg- 

 ments without dorsal plates ; divisions between thoracic and abdomi- 

 nal segments distinct, the annuli very poorly defined; surfaces of both 

 thoracic and abdominal segments densely covered with very short 

 pale hairs, the only distinguishable setulose hairs being on lateral mar- 

 gins of posterior annuli of segments. Apical abdominal segment tube- 

 like, chitinized but not conspicuously darker than preceding segments, 

 its length about 3 times as great as its greatest width ; apical papillae 

 very small, fringes short (Fig. 9). 



Pupa. — Length, 2 mm. Yellowish testaceous. 



Prothoracic organ (PI. XXXIX, Fig. 5) of moderate size, taper- 

 ing apically, and with a series of small spiracle-like protuberances 

 along one side; eyes large; antennae considerably thickened (male) ; 

 front view of head and appendages as in Figure 16. Abdominal ar- 

 mature weak; dorsal segments, except basal, each with a transverse 

 posterior series of widely separated spinules and an interrupted medi- 

 an series of very minute setulae (Fig. 17) ; ventral segments (Fig. 

 18), except the apical one and those below wings, each with a posterior 

 and anterior transverse series of closely placed spinules and a median 

 transverse series of 4 rather widely placed spinules; apical segment 

 with 3 spines on each side, the two lower ones very closely placed; 

 apical thorns on upper margin strong ( Fig. i ) . 



The above descriptions were drawn from larvae and pupae ob- 

 tained from cow dung in November, 191 5, and April, 1916, the for- 

 mer at Urbana and the latter at White Heath, 111. 



The small size of this species makes it a very difficult one to rear 

 and isolate the stages and exuvia successfully. 



Originally described from Sea Cliff, N. Y., and subsequently re- 

 corded from Mesilla, N. Mex. Probably of general occurrence 

 throughout North America. 



PsYCHODA SUPERB A Banks 



Psychoda siiperla Banks, Can. Ent., Vol. 26, 1894, p. 332. 



Larva (PI. XXXIX, Fig. 13). — Length, 5-5.5 mm. Grayish 

 white ; head, chitinized dorsal plates, and apical segment brown. 



Dorsal surface of head with several long hairs ; antenna termi- 

 nating in 2 stout bristles and 2 weak hairs (Fig. 12). All thoracic 

 and abdominal segments with a single large chitinized plate on dorsum 

 of each annulus, those of prothoracic and first mesothoracic annuli 



