. Annual report of the Regents. New York State Museum; Science. AQUATIC INSECTS IN THE ADIRONDACKS 473 Labium short and stout, median lobe with a narrow median cleft and denticulate margin; lateral lobes truncate on end, scarcely denticulate : no raptorial setae. Legs stout, with prominent, twisted, hair-fringed, longitudinal carinae; tarsi 3-3-3 jointed. Wing cases laid parallel along the back, their apices reaching the mid- dle of the fifth segment. Abdomen tapering beyond the fifth segment with thin flaring lateral margins showing on each of segments 4-9 an angle at the middle and a flat to
. Annual report of the Regents. New York State Museum; Science. AQUATIC INSECTS IN THE ADIRONDACKS 473 Labium short and stout, median lobe with a narrow median cleft and denticulate margin; lateral lobes truncate on end, scarcely denticulate : no raptorial setae. Legs stout, with prominent, twisted, hair-fringed, longitudinal carinae; tarsi 3-3-3 jointed. Wing cases laid parallel along the back, their apices reaching the mid- dle of the fifth segment. Abdomen tapering beyond the fifth segment with thin flaring lateral margins showing on each of segments 4-9 an angle at the middle and a flat tooth at the apex, and with a dorsal row of hairy tubercles on seg- ments 5-9, parallel to the lateral margin but nearer the median line: ap- pendages obtuse, the superior with a broad, shallow, apical emargination. The eggs are deposited in wet, boggy places, when there is hardly any water standing, and the nymph lives in the mud in such places. Subfamily cordulegasterinae A small group of large species, inhabiting mainly clear streams that flow through upland marshes, spring bogs, etc. The imagos are strong of flight, and are oftenest seen cours- ing back and forth over some small stream, flying on a regular beat, and passing and repassing the same point at intervals of a few minutes. The collector may take advantage of this habit, and so station himself that he may reach the specimen as it passes, and capture it^ if dextrous with a net. The nymphs live on the bottom in shallow water, buried in clean sand or in vegetable silt. Though buried they do not burrow, but descend by raking the sand from beneath them by sweeping, lateral movements of the legs. When deep enough, they kick the sand up over the back till only the elevated tips of the eyes and the respiratory aperture at the tip of the abdomen are exposed. By placing a Hve nymph in a dish of sand and water and watching, its method may be observed in a very few minutes. The whole comical performance reminds one strongly of t
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Keywords: ., bookauthorne, bookcentury1800, bookdecade1880, booksubjectscience
