32. 

 HYDROMETRA STAGNORUM. 



Order Hemiptera. Fam. Hydrometidae Leach. 



Type of the Genus H. Stugnorum. 



Hydrometra Z.a^, Fa6. C\me\ Li7w. (ierris Fa6. Aquarius Sc/ie/- 



lenhurgh. 



Antenn(B exserted, filiform, inserted on the sides of the head 



towards the apex, 4-jointed, third joint very long. (4.) 



Rostrum inflected, transversely striated, thickest towards the 



base and apex, obscurely 3-jointed, second joint very long. (2.2.) 



Lahrum small, linear, acute. (3. the profile, 3. a. the underside.) 



Mo??'/i6/fAs' and 1 ,., ^ • ., , ^, 



,. ... > like setae, passmg through the rostrum. 



Head longer and narrower than the thorax, porrecfed, elongate, cylin- 

 dric, thickened at the end. Eyes globose, prominent, inserted on the 

 sides before the middle of the head. Thorax cijlindric, anterior part 

 narrowed. ScuteWum minute. Abdomen more or less Jiliform, di- 

 lated in the middle ; margins acute; terminal joint much largtr in the 

 male than female, cylindric, niucronated. Elytra coriaceous, long 

 and narrow. Wings semitransparent, long and narrow. Feet long, 

 slender, attached to the sides of the abdomen, anterior the shortest, 

 posterior the longest. Tarsi indistinctly '3-jointed, first joint very 

 minute. Claws inserted in a fissure at the extremity of the last joint 

 of the tarsi, distinctly bifid only in the posterior pair. (G. afore leg.) 



Stagnorum Linn. Faun. Suec. 971. Fab. Ent. Syst. t. 4. p. 188. n.4. 

 Velvety black. Thorax sometimes testaceous with a slight chan- 

 nel down tlie back. Abdomen with 2 nearly parallel lines 

 down the back ; edges dilated to the last segment with a griseous 

 spot at each joint, sliining down the centre. Elytra testaceous, 

 clouded with black nerves. Wings fuscous with darker nerves. 

 Feet and antenna; ferruginous or fuscous. 



In the Cabinets of the British Museum and the Author. 



These curious insects are common in almost every brook and 

 pond during tlie spring, where they may be seen with Vdia 

 and Gcrris gliding along tiie surface of the water. Most of 

 them are either ai)terous, or have only short parallel elytra ; 

 but in the British jNIuseum are two females presented to that 

 establishment by Dr. Leach, which iiave long elytra crossing 

 each other when the insect is at rest, and perfect wuigs as ex- 



