﻿32. 

 HYDROMETRA STAGNORUM. 



Order Hemiptera. Fam. Hydrometidae. 



Type of the Genus, Cimex stagnorum Linn. 



Hydrometra Lat., Fab., Curt. — Gerris Fab. — Aquarius Schel.— 

 Cimex Linn. 



AntenncE porrected, very slender and setaceous, inserted on 

 shoulders at the base of the clypeus, as long as the head and 

 thorax, remote, pubescent and 4-jointed, basal joint the short- 

 est and stoutest, 2nd a little longer, 3rd thrice as long, 4th half 

 as long as the 3rd (4). 



Rostrum inflected, shorter than the head, very slender (2). 

 Labrum linear, slender and acute (3 the profile, 3 a the under- 

 side). 



Mandibles and maxillae setiform. 



Labium transversely striated, thickened towards the apex, in- 

 distinctly triarticulate, basal joint short, 2nd very long, 3rd not 

 longer than the 1st; conical at the apex (2*). 

 Males smaller than the females. Head twice as long as the thorax, 

 and much narrower, cylindric, dilated at the apex ; the clypeus nar- 

 rowed : eyes lateral globose and very promitient, inserted before the 

 middle (1, the profile). Thorax elongated, slightly constricted at the 

 middle, invisibly united beneath to the abdomen : scutel none, or se- 

 micircular and concealed. Abdomen depressed, long and linear, the 

 sides broadly margined and slightly convex in the females, with the 

 apex acute and furnished with an incurved hook ; ajiical joint oblong, 

 narrowed, and tvith a minute tubercle in the males. Elytra coria- 

 ceous, either as short as the thorax and narrow, or thrice as long and 

 elliptical, with an interrupted subcostal nervure, another parallel 

 to the interior margin, and 2 transverse ones towards the apex : 

 wings either none or nearly as long as the elytra, submembranous , 

 with 2 longitudinal nervures and a transverse one near the apex. 

 Legs long and very slender, attached to the sides, anterior the short- 

 est, posterior the longest : coxae, hinder remote : thighs cylindric, 

 slender ; tibiae very slender : tarsi short, very slender, indistinctly 

 triarticulate, basal joint very minute, 2nd and 3rd elongated, clavate, 

 of equal length: claws 2, equal and very slender (6, afore leg). 



Stagnorum Linn. — Curt. Guide, Gen. 1082. 1. 



In the Author s and other Cabinets. 



These curious insects are common in almost every brook 

 and pond during the spring, where they may be seen with Ve- 

 lia, pi. 2, and Gerris, pi. 553, gliding along the surface of the 

 water. Most of them are either apterous, or have only short 

 parallel elytra, whilst a few have ample elytra, decumbent and 

 horizontalvvhen the insects are at rest, and also perfect wings, 

 as exhibited in the specimen represented flying in the plate. 



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