NO. 2ir.o. ^OME NEVy HETEROPTEROUS HEMIPTERA—BERGROTH. 237 



one-third the length of the mesosternuni and as long as the two first 

 segments and half the third segment of the venter taken together, 

 with the orificiimi placed in a foveate impression near the hind 

 margin. Hemelytra a little longer than abdomen. Venter as long as 

 mesosternimi ; sixth segment deeph^ arcuately sinuate at apex, in the 

 middle a little longer than the preceding segment; apical angles 

 acute, almost reaching second male genital segment which is about 

 twice the length of first genital segment. Fore femora almost as 

 long as mesosternuni, somewhat thickened toward base; second joint 

 of fore tarsi more than twice the length of first joint. Middle coxae 

 not quite reaching base of hind acetabula. Middle and hind femora 

 subequal in length and but slightly shorter than the body; middle 

 tibiae a little shorter than the femora and more than three times 

 longer than the tarsi ; hind tibiae and tarsi together about half the 

 length of the femora. 



Length. — Male, T mm. 



Ttjpe.— Cat No. 20154, U.S.N.M. 



Remarkable by its dull color, all other known species being shin- 

 ing, and by the very short basal joint of the fore tarsi. 



Note. — The confusion prevailing in the genus Gerris is great, and 

 is chiefly due to the fact that some authors have confounded quite 

 distinct genera with Gems, often even without indicating to what 

 subgenera or groups of " Gerris " in this wide sense their species 

 belong, and without mentioning such characters from which the 

 species could be systematically located. Of that sort are all the 

 Indian species described by Distant. Aquarius Schellenberg {Uy- 

 grotrecKus Stal) can be considered a subgenus of Gerris Fabricius 

 {Limnotrechus Stal), but Liinnoporus Stal, Tenagogonus Stal {Lim- 

 nometra Mayr), and Limnogonus Stal are good genera. Tenagogo- 

 nus was founded in 1853 without a type, but in 1855 Stal described 

 a single species of this genus, albovittatus., from Natal, which thus is 

 the type. This species was omitted by Stal himself in his Hemip- 

 tera Africana and by Lethierry and Severin in their Catalogue, but 

 Kirkaldy had seen specimens (probably also types) of it, and says 

 that it is a Limnometra. 



CYLINDROSTETHUS QUADRIVITTATUS. new species. 



Apterous form. — Above fulvous with a distinct buffy tint, beneath 

 pale testaceous; clypeus and adjacent parts of juga, apex of anten- 

 niferous tubercles, an oblong spot at posterior half of inner margin 

 of eyes, two vittae slightly curved outward to pronotum, four vittae 

 to mesonotum (the two median ones shortly interrupted [male] or 

 narrowed [female] behind the middle), two vittae to metanotum, 

 dorsum of abdomen (except the first [female] or three first [male] 



