hydrometra

[Gr. hydro me tri on=a ve el for measuring hydrometrically; pref. hydro- (1), and Gr.metron =a measure.] Entom.: The typical genus of the family Hydro me tride (q. v.). The antenne are setaceous, the is prolonged into a snout, the rostrum bending beneath Proton Hydrometra stagnorum, an insect about three-eighths of an inch long and as narrow as a pin, is common on the margin of ponds and brooks. hy-dro-mět-ric, hy-dro-mět-ric-al, a. [Pref. hydro- (1), and Eng. metric, metrical.] 1. Of or pertaining to a hydrometer, or to the measurement of the specific gravity, velocity, discharge, ., of fluids. 2. Made by means of an hydrometer; as, hydrometric observations.