. Bulletin. Natural history; Natural history. in the male of longiseta the lobe on the posterior margin of the eighth abdominal sternite is rounded, figs. 94 and 95, and the subanal lobes at the tip of the abdomen are long and slender; whereas in the male of mortiiona the lobe is more distinctly truncated or square and the subanal lobes are shorter and somewhat stouter; (2) in the female of longiseta the subgenital plate, figs. 94 and 95, is much produced, rounded and strongly sclerotized, whereas in the female of morniona it is much less produced and more weakly sclerotized; (3) in longiseta,
. Bulletin. Natural history; Natural history. in the male of longiseta the lobe on the posterior margin of the eighth abdominal sternite is rounded, figs. 94 and 95, and the subanal lobes at the tip of the abdomen are long and slender; whereas in the male of mortiiona the lobe is more distinctly truncated or square and the subanal lobes are shorter and somewhat stouter; (2) in the female of longiseta the subgenital plate, figs. 94 and 95, is much produced, rounded and strongly sclerotized, whereas in the female of morniona it is much less produced and more weakly sclerotized; (3) in longiseta, both sexes, the pronotum has dark brown embossings that are more or less strongly contrasting in color with the remainder of the pronotum, figs. 94 and 95, whereas in mormona the entire area, except for the median yellowish stripe, is more uniformly suffused with brown. In the Illinois Natural History Survey collection is a series of males, females and exuviae from El Paso, Tex., which I am identifying with some hesitation as longi- seta. All of the males of this series are brachypterous, fig. 96. Compared with longiseta specimens from Illinois and other states, fig. 95, these Texas specimens have the dark area on the dorsum of the head anterior to the ocelli more suffused, fig. 94, and the modified subanal lobes appear shorter and stouter and in this respect Abdominal segments. 2 Subgenital plate d" Abdominal TERGiTEs Fig. 94.—Isoperla longiseta, drawn from Texas specimens. Fig. 95.—Isoperla longiseta, drawn from Mississippi River valley Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Illinois. Natural History Survey Division. Urbana, State of Illinois, Dept. of Registration and Education, Natural History Survey Division
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