. Fresh-water biology. Freshwater biology. 728 FRESH-WATER BIOLOGY 196 (193) Post-abdomen of moderate length; ventral (upper) margin straight, or nearly so; greatest width behind anus 197 197 (200) Angle of post-abdomen sharp, with cluster of spines at apex. 198 198 (199) Teeth at infero-posteal angle of valves; no hook on first foot of female Pleuroxus denticulatus Birge 1877. Infero-posteal angle with small tooth- like spines. Post-abdomen moderately long, straight, very little narrowed toward apex; length of post-anal part times, or more, that of anal emargination; apex truncate; with c
. Fresh-water biology. Freshwater biology. 728 FRESH-WATER BIOLOGY 196 (193) Post-abdomen of moderate length; ventral (upper) margin straight, or nearly so; greatest width behind anus 197 197 (200) Angle of post-abdomen sharp, with cluster of spines at apex. 198 198 (199) Teeth at infero-posteal angle of valves; no hook on first foot of female Pleuroxus denticulatus Birge 1877. Infero-posteal angle with small tooth- like spines. Post-abdomen moderately long, straight, very little narrowed toward apex; length of post-anal part times, or more, that of anal emargination; apex truncate; with cluster of fine, straight denticles at apex and 8-12 anterior to these. Color greenish or yellowish, usu- ally transparent. Length, J, mm.; J, mm. Common everywhere in weedy water. Fig. Z141. Pleuroxus MM, 199 (198) Infero-posteal angle rounded; first foot of female with stout hook. Pleuroxus hamulatus Birge 1910. Infero-posteal angle rounded, without teeth; valves reticulated; also marked by very fine striae, which run nearly longitudinally. Rostrum long, recurved. Keel of labrum small, rounded, prolonged. Post-abdomen much like P. denticulatus, but with apex more rounded and denticles not so crowded there. Denticlesabout 12-14. J unknown. Color hom-yellow, often dark on dorsal side like P. striatus. Length, 9, ca. mm. New England and southern states; prob- ably a coastal form; not reported from north central region. Common in pools and weedy 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
