. Bulletin. Natural history; Natural history. and with a pair of short, stubby lateral processes. Oedagus with base sharply angled and slightly constricted at the angulation, then gradually increasing in size to apex. The dorsal sclerotized plates are large and fit into the abrupt angle at the apex of the oedagus. Be- hind this is a pair of short membranous lobes, each bearing at its end a short, buttonlike sclerotized spine. The termi- nal projection of the oedagus is angled down more than usual and bears a single invaginated cluster of spines and a pair of thin, membranous lateral appendages
. Bulletin. Natural history; Natural history. and with a pair of short, stubby lateral processes. Oedagus with base sharply angled and slightly constricted at the angulation, then gradually increasing in size to apex. The dorsal sclerotized plates are large and fit into the abrupt angle at the apex of the oedagus. Be- hind this is a pair of short membranous lobes, each bearing at its end a short, buttonlike sclerotized spine. The termi- nal projection of the oedagus is angled down more than usual and bears a single invaginated cluster of spines and a pair of thin, membranous lateral appendages which reach one-third of the way to the base of the oedagus; these appendages have no spines at their apex but instead a circular opening around which are several small setae. Holotype, male.—Greer, Missouri: March 28, 1937, at spring near town, T. H. Prison. Paratypes.— .Arkansas. — Mammoth Springs: June 6, 1937, H. H. Ross, 2d'. Hydropsyche vexa new species This species differs from piatrix in having spines in the apex of the disto- lateral arms of the oedagus and from others in having only short and very. Fig. 77.— Hydropsyche piatrix Fig. 78.—Hydropsyche vexa slender spines on the dorso-lateral arms of the oedagus. Male.—Length 9 mm. Color and general structure and characteristics ex- actly as in piatrix. Genitalia as in fig. 78. Tenth tergite fairly long with a relatively sharp angle at its apex, and with a pair of long, slender lateral pro- cesses. Oedagus with the basal portion wide and low and a distinct thickening near middle; dorso-lateral appendages membranous, each tipped with a short, slender spine; apex of oedagus with a. 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
Size: 1945px × 1284px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
