. Fresh-water biology. Freshwater biology. AQUATIC INSECTS 937 ui (20) 22 (23) 23 (22) 24 (2S) 25 (24) Ocelli wanting 22 Front tibiffi with three spurs. . Family Polycentropidae. Spurs of the front tibiae fewer than three. , 24 Anterior branch of the radial sector in the fore wing forked. Family Hydropsychidae. Anterior branch of the radial sector simple. Family Fig. 1391. The wings of a caddisfly, Uydropsyche, 26 (3) MaxUlary palpi with fewer than five joints 27 27 (28) Maxillary palpi with four joints; ocelli present. Males. Family Phryganeidae. 28 (27) Maxillary palpi with t
. Fresh-water biology. Freshwater biology. AQUATIC INSECTS 937 ui (20) 22 (23) 23 (22) 24 (2S) 25 (24) Ocelli wanting 22 Front tibiffi with three spurs. . Family Polycentropidae. Spurs of the front tibiae fewer than three. , 24 Anterior branch of the radial sector in the fore wing forked. Family Hydropsychidae. Anterior branch of the radial sector simple. Family Fig. 1391. The wings of a caddisfly, Uydropsyche, 26 (3) MaxUlary palpi with fewer than five joints 27 27 (28) Maxillary palpi with four joints; ocelli present. Males. Family Phryganeidae. 28 (27) Maxillary palpi with two or three joints 29 29 (30) Maxillary palpi filiform with cylindric smooth joints; fore tibiae with a single spur. Males Family Limnophilidae. 30 (29) Maxilary palpi hairy or scaly, appressed against and often covering the face; fore tibiae with two spurs. Males. Family Sericostomatidae. KEY TO NORTH AMERICAN AQUATIC BEETLES Adults 1 (2) Hind tarsi with the antepenultimate segment broadly bUobed, and receiving the rudimentary penultimate segment (which is closely fused with the base of the last segment) in its apical notch. . Family Chrysomelidae. 2 (i) Hind tarsi with the last three segments free and similar in form. . 3 3 (8) Hind legs shorter than the fore; eyes four, two above and two on the under surface of the head. . Family Gyrinidae . 4 4 (7) Last abdominal segment rounded posteriorly and smooth below. . 5 5 (6) Wingof the metasternumCw, Fig. 1392) broadly triangular. Dineutes. 6 (s) Wing of the metasternura narrow, elongate, widened only at its extreme outer end. 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 Ward, Henry Baldwin, 1865-1945; Whipple, George Chandler, 1866-1924. joint author. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
