August, 1944 



Ross: Caddis Flies of Illinois 



53 



with a large, thick brush on the 



mesal side, fig. 196 



Phylocentropus, p. 54 



Mandibles longer, fig. 197, with only 

 a thin brush on left mandible, none 

 on right 3 



3. Right mandible with a single dorsal 



tooth which only partially hides the 

 ventral row of teeth; on the left 

 mandible the dorsal row of teeth 

 does not hide the ventral row, figs. 



197, 198 4 



Right mandible with two large dorsal 

 teeth which completely overhang 

 and hide the ventral row; on the left 

 mandible the dorsal row of teeth 

 overhangs and hides the ventral 

 row, fig. 199 5 



4. Basal segment of anal appendages 



(tenth segment) without hair, fig. 

 192; left mandible with basal tooth 

 small and with a linear brush on 



mesal face near base, fig. 197 



Neureclipsis, p. 56 



Basal segment of anal appendages 

 (tenth segment) with long hair, fig. 

 193; left mandible with basal tooth 

 large, subequal to one above and 



with brush small, fig. 198 



Polycentropus, p. 58 



5. Ninth sternite with a wide, T-shaped, 



reticulate area; tenth segment short, 

 with an extensive patch of minute 

 spinules on venter, figs. 200, 201 . . . 



Psychomyiid Genus B, p. 74 



Ninth sternite without a reticulate 

 area; tenth segment long, without 

 spinules but with an extensive patch 

 of long hair on venter, similar to fig. 

 193 Psychomyiid Genus A, p. 73 



Pupae 



1. Apex of mandibles with a long, termi- 

 nal "whip," fig. 202 



Psychomyia, p. 75 



Fig. 202. — Psychomyia flavida pupa, man- 

 dible. 



Fig. 203. — Polycentropus cinereus pupa, 

 mandible. 



Fig. 204. — Phylocentropus placidus pupa, 

 mandible. (After Vorhies.) 



Apex of mandibles without a terminal 



"whip," fig. 203 2 



2. Terminal segment of abdomen with 4 

 bushy processes, 2 apical and 2 baso- 



lateral Phylocentropus, p. 54 



Terminal segment with only 2 apical 

 bushy processes, fig. 205 3 



Fig. 205. — Polycentropus cinereus pupa, api- 

 cal processes. 



Fig. 206. — Neureclipsis crepuscularis pupa, 

 apical processes. 



Fig, 207. — Psychomyia flavida pupa, apical 

 processes. 



3. Apical lobes of abdomen evenly 



rounded at apex, fig. 205 



Polycentropus, p. 58 



Apical lobes of abdomen with mesal 

 margin straight, mesal angle sharp 

 and outer margin curved, fig. 206. . 

 Neureclipsis, p. 56 



Adults 



1. Front tibiae with a preapical spur. ... 2 

 Front tibiae without a preapical spur 6 



2. Both pairs of wings with Rs present 



and branching from Ra at radial 



crossvein, fig. 208 



Phylocentropus, p. 54 



Both pairs of wings with Rs either 



