. Bulletin. Natural history; Natural history. 324 Illinois Natural History SuRviiv Hullhtin lol. 22, Art. 2 areas milky; veins pale aiul almost coii- colorous with connecting nicnibrane. Abdomen, Hg. 100. with no distinctive features except for shape of subgenital plate on posterior margin of eighth ster- nite; subgenital plate extends somewhat over ninth stcrnite, is broadl\ rounded on posterior margin, slightly indented at tip, and with a concave, transverse valley at. cf Abdominal segments Fig. 100.—Isoperla orata. its base; subgenital plate, as viewed from side, tends to extend awa> fro
. Bulletin. Natural history; Natural history. 324 Illinois Natural History SuRviiv Hullhtin lol. 22, Art. 2 areas milky; veins pale aiul almost coii- colorous with connecting nicnibrane. Abdomen, Hg. 100. with no distinctive features except for shape of subgenital plate on posterior margin of eighth ster- nite; subgenital plate extends somewhat over ninth stcrnite, is broadl\ rounded on posterior margin, slightly indented at tip, and with a concave, transverse valley at. cf Abdominal segments Fig. 100.—Isoperla orata. its base; subgenital plate, as viewed from side, tends to extend awa> from abdomen much as in truncata Frison. Length to tip of wings 11 mm.; length to tip of abdomen 7 mm. Mali:.— Head, thorax and basal ab- dominal segments in general similar to those of female, but slightly smaller in size. Important differences or structures are as follows: tenth tergite not cleft, fig. 100, subanal lobes weakly developed and but slightly visible from above; ninth sternite, fig. 100, produced backwards so that apical tergites are not visible in ventral view; eighth sternite with a shal- lowly recessed but distinct lobe in middle of posterior margin. Holotype, female. — Ciatlinburg, Le Coiite Creek, Tenn.: reared from nymph, May 14, 1939, T. H. Frison & H. H. Ross. Allotype, male.—Same data as for holo- type. Paratypes.——Gatlinburg: Same data as for holotype, 5$ ; same data as for holotype except not reared, 5 c?, 18$ ; June 14, 1940, T. H. Frison rt al., 1$, reared from nvmph; same data except not reared, 16 9 ; fork of Little Pigeon River, May 27, 1934, T. H. Frison, \i, 4$; Fighting Creek Gap, Mav 15, 1939, T. H. Frison & H. H. Ross, 1^, 2$.' Elkmont, June 13, 1940, T. H. Frison rl al., 19. New York.—Keene, tributary of Sable Riv- er: June 20, 1941, T. H. Frison & H. H. Ross, 3 (^ , 49. EuBA Mills, Adirondack Park: June 20, 1941, T. H. Frison & H. H. Ross, \i, 19. , Black River: June 19, 1941, T. H. Frison
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Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
