| OCR Text |
Show 194 undescribed is nymphs as follows: Mature Nymph (in alcohol).Length: body 8-9; caudal filaments 7.5-8.5 mm. General color brown. Antennae dark brown basally, white apically; head brown with dark brown to black shading mediad of antennal sockets, in some speci mens extending over entire head except for lateral margins. Prothoracic notum dark brown with pale margins and pale, thin median stripe; mesothoracic notum brown with anterior margin and antero-lateral corners dark brown, and with median pale stripe; thoracic sterna white with dark brown inverted U shaped shading on mesosternum; femora light brown with large white basal-median spots, dark brown to black median macula, dark brown apex, and with long spines on posterior margin; tibiae and tarsi light brown with dark brown shading on basal one-eighth of" tibiae; tarsal claws light brown with 3-5 denticles. Abdomen with gills on segments 1-7 as in Fig. 115, and with small sharp postero-lateral projections lateral of gill insertions; abdominal terga 1-10 brown, darker on 6-10, and with dark brown sublateral spot or spots on each segment; abdominal sterna 1-7 brown, darker laterally and with paired submedian pale stripes, sterna 8-9 dark Caudal filaments dark brown at extreme base, white brown. apically, and with small spines at apex of each segment. Taxonomy and Both to B. the Biology distinguish futilis adults feet from of and 520 large rocks early in the difficult closely related . hageni Eaton and but this apparently species early emergence of the May and June aid in distinguishing in this moderately flowing 4,000 of the McDunnough, Nymphs to from are of adults and nymphs to in species rivers sample 64°F. season as and summer They and among have are gravel. Edmunds been collected above streams daytime water the species. from slow elevations temperatures found most commonly under adul ts usually emerge The (1952b) has of reported them from |
