August, 1944 



Ross: Caddis Flies of Illinois 



81 



width, apex not narrowed, fia;s. 307, 



313 r 



7 



7. Third abdominal tergite with posterior 



plates ovoid, fig. 314 



Cheumatopsyche, p. 108 



Third abdominal tergite with posterior 



plates long and linear, fig. 315 



Hydropsyche, p. 86 



Adults 



1. Head with anterior warts large and 



swollen, posterior warts much 

 smaller, fig. 317; slender species 

 with very long antennae and with 



pictured wings, fig. 420 



Macronemum, p. 1 14 



Head with anterior warts small or in- 

 distinct, posterior warts large, figs. 

 318-320 2 



2. Front wings with R4 and Rs running 



very close together at base and form- 

 ing a long, narrow V, fig. 330 



Smicridea, p. 85 



Front wings with Ri and Rs separating 

 rapidly at base and not running 

 close together, figs. 331-334 3 



3. Hind wings with apex round and 



with Sc and Ri bowed deeply at 



apex, fig. 331 Diplectrona, p. 84 



Hind wings either with Sc and Ri not 

 markedly bowed, fig. 333, or both 

 wings with apical margin incised, 

 fig. 332 4 



4. Second segment of maxillary palpi 



distinctly shorter than third seg- 

 ment, fig. 322 5 



Second segment of maxillary palpi as 

 long as or longer than third segment, 

 fig. 323 8 



5. Genitalia with aedeagus and claspers 



(males) 6 



Genitalia without aedeagus or claspers 

 (females) 7 



6. Eighth segment with sternite forming 



a short, wide projection extending 



under genital capsule 



Parapsyche, p. 83 



Eighth segment with sternite not pro- 

 jecting under genital capsule 



Arctopsyche, p. 83 



7. Middle tibiae with basal two-thirds 



almost cylindrical, fig. 324 



Parapsyche, p. 83 



Middle tibiae greatly widened and 



flattened, fig. 325 



Arctopsyche, p. 83 



8. Front tibiae without apical spurs, fig. 



326 Potamyia cf , p. 85 



Front tibiae with well-developed spurs, 

 fig. 327 9 



Eyes situated distinctly forward from 

 posterior margin of head, figs., 318, 

 319; front and hind wings similar in 

 shape, figs. 332, 333 10 



Eyes situated at or near posterior 

 margin of head, fig. 320; front wings 



Fig. 317. 



Fig. 318. 



Fig. 319. 



Fig. 320. 



Fig. 321.- 

 palpus. 



Fig. 322. 

 palpus. 



Fig. 323. 

 palpus. 



Fig. 324.- 



Fig. 325. 

 tibia. 



Fig. 326. 



Fig. 327,- 



Fig. 328.- 



Fig. 329. 



— Macronemum zebratum, head. 

 — Oropsyche howellae, head. 

 —Aphropsyche aprilis, head. 

 — Potamyia flava, head. 

 -Macronemum zebratum, maxillary 



—Arctopsyche lagodensis, maxillary 



— -Hydropsyche betteni, maxillary 



—Parapsyche elsis 9, middle tibia. 

 —Arctopsyche lagodensis 9, middle 



—Potamyia flava c?", front tibia. 

 —Potamyia flava 9, front tibia. 

 —Potamyia flava 9, head. 

 —Cheumatopsyche campyla, head. 



