August, 1944 



Ross: Caddis Flies of Illinois 



29 



figs. 59, 63, usually of same length, 

 or some segments with long hair 

 brushes, fig. 60 12 



10. Anterior tibiae with a preapical spur 



as in fig. 21 



Psychomyiidae, p. 5 1 



Anterior tibiae without a preapical 

 spur 11 



11. Hind wings with R almost or entirely 



normal in its course, with 4 or all 5 

 branches distinct and the stem dis- 

 tinct from Sc, fig. 334; anal area at 

 least as large as in fig. 333; mesoscu- 



tum without warts, fig. 80 



Hydropsychidae, p. 76 



Hind wings with R much reduced, the 

 stem either absent or fused with Sc 

 and only 3 or 4 branches present, 

 figs. 212,213; anal area reduced to a 

 small area as in fig. 212; mesoscutum 

 with a pair of small warts, fig. 81 . . . 

 Psychomyiidae, p. 51 



12. Middle tibiae without preapical spurs 



and with a row of black spines, fig. 



69 13 



Middle tibiae with preapical spurs, 

 with or without a row of spines, figs. 

 73-75 17 



13. Pronotum consisting of a lateral pair 



of erect, platelike warts separated 

 by a wide, mesal, excavated collar 

 which is usually hidden by the pro- 

 duced, angulate margin of the meso- 

 notum, fig. 82; mesonotum with 

 short scutellum and with scutal 

 warts represented by a long, irregu- 

 lar line of setate spots; antennae 

 always very long and slender, fig. 



863 Leptoceridae, p. 209 



Pronotum with warts much closer to- 

 gether, not platelike, and usually 

 prominent, fig. 83; mesonotum with 

 scutal warts either small, fig. 85, or 

 absent, fig. 83; antennae as stout as 

 or not longer than those in fig. 702 14 



14. Hind wings each with anterior margin 



cut away beyond middle, fig. 76, 

 with a row of hamuli along straight 



basal portion of margin 



Helicopsychidae, p. 266 



Hind wings each with anterior margin 

 straight or evenly rounded, fig. 874 15 



15. Middle and hind tarsi with a crown of 



4 black spines at apex of each seg- 

 ment and only a few preapical spines 

 arranged in a single row on the basi- 

 tarsus, fig. 70; apical spurs of middle 

 tibiae nearly half length of basitar- 



sus, fig. 69 Beraeidae, p. 208 



Middle and hind tarsi with apical 

 spines more separated and not form- 

 ing a crown, and with numerous pre- 



apical spines on all segments, 

 arranged in a double row on the basi- 

 tarsus, fig. 71; apical spurs of middle 

 tibiae not more than one-third 

 length of basitarsus, fig. 72 16 



16. Mesoscutum with a deep, antero-mesal 



fissure with scutal warts near meson, 

 fig. 88; head with posterior warts 

 diagonal and tear-shaped, fig. 78; 

 front wings with a long crossvein 

 between Ri and R2 and with Cuj 

 joining apex of Cuib directly, fig. 77 



Sericostomatidae, p. 266 



Mesoscutum with only a shallow an- 

 tero-mesal crease, with scutal warts 

 some distance from meson, fig. 84; is. 

 head with posterior warts linear and 

 transverse, fig. 79; front wings with- 

 out a crossvein between Ri and R2 

 and with Cut connected to apex of 



Cuib with a crossvein, fig. 890 



Brachycentridae, p. 260 



17. Middle femora each with a row of 6-10 



black spines on antero-ventral face, 



fig. 73 Molannidae, p. 205 



Middle femora each with none to 2 

 black spines on antero-ventral face 18 



18. Mesonotum with small, rectangular 



scutellum, and with scutal warts 

 represented by a linear area of small, 

 setate spots extending the full length 



of the scutum, fig. 87 



Calamoceratidae, p. 



Mesonotum with longer and pointed 

 scutellum, and with scutal warts 

 oval or lanceolate and short, fig. 84 



19. Mesoscutellum with a single large oval 



or round wart which extends the full 

 length of the scutellum, fig. 89, and 

 may occupy almost the entire scu- 

 tellum, fig. 86 



Mesoscutellum with 2 warts which are 

 smaller and confined to the anterior 

 half of the scutellum, figs. 84, 90. . . 



20. Mesoscutellum round and distinctly 



domelike, the wart appearing to 

 occupy most of the sclerite; scutum 

 with mesal line only faintly indi- 

 cated, fig. 86; tibial spurs not hairy; 

 maxillary palpi of males 5-segmented 



Odontoceridae, p. 209 



Mesoscutellum triangular, only slight- 

 ly convex, the wart elongate and 

 occupying only the mesal portion of 

 the sclerite; scutum with distinct 

 mesal depression, fig. 89; tibial 

 spurs hairy; maxillary palpi of males 

 3-segmented Goeridae, p. 256 



21. Middle tibiae with an irregular row, 



middle tarsi with a long double row 

 of spines, preapical spurs of tibiae 

 bare, shorter and situated about 



209 



19 



20 



21 



