June, 1916 Bulletin of the Brooklyn Entomological Society 55 



Apterous form : Pronotum stout, transversely impressed about one 

 fourth its length from the anterior margin, two longitudinal impressions 

 from the anterior margin at the eyes meet it, producing deep f oveae at 

 the points of juncture; rounded truncate posteriorly with a somewhat 

 broad explanate margin. Six abdominal segments and two genital visible 

 dorsally, six ventrally (as in the winged), segments except the first of 

 nearly equal length, abdomen widest at fifth and sixth segments, with two 

 deep longitudinal lateral grooves. Connexival edges blunt, rounded ; gen- 

 ital segment quadrilateral, twice as broad as long, truncated, with the 

 second genital segment projecting beyond like a small blunt knob. Other 

 structural characters as in the winged, except two small, triangular wing- 

 pads. * 



Color brown as in the winged, except that the specimen in hand is some- 

 what darker in shade. Silvery pilose, two small anter-lateral patches on 

 pronotum, posterior connexival edges from second to sixth segment, pos- 

 terior middle of third dorsal segment, broadening in fourth and broadly 

 lateral in fifth and sixth, fifth segment with a small posterior median 

 patch. Milk white, vestigial wing pads projecting beyond posterior edge 

 of pronotum. Winged, long., 5.3 mm. ; lat, 2 mm. at humeri. Apterous, 

 long., 5 mm.; lat, 1.7 mm. 



Described irom one winged male, " Fla., Wagner — E. I. ", with 

 last two joints of antennae missing; and one apterous male, with 

 two joints of right antennae missing, from Spring Creek, Decatur 

 Co., Georgia, June 7-23, 1912. J. C. Bradley. 



Type, winged male in my collection. 



Paratype (and morphotype), apterous male in collection J. C. 

 Bradley. 



Rhagovelia Mayr. 1865, Verh. zool. hot. Ges. Wien, XV: 445. 



Biucula Stal, 1865, Hem. Afr., Ill: 167. Neovelia F. B. 

 White, 1879, Journ. Linn. Soc. Lond., Zool., XIV: 487. 

 Trochopus Carpenter, 1898, Ent. Mo. Mag., XXXIV: 78. 



Rhagovelia, next to Rheumatobates, is perhaps the most in- 

 teresting genus of the waterstriders in regard to special adapta- 

 tion to a peculiar habitat, to be found only in running streams. 

 The species are dimorphic, but in our latitude the fully winged 

 are rarely seen. Little is known as to their breeding habits or 

 other phases of life. The Atlantic States forms are easily sep- 

 arated, aside from the difference of habitat, by the following key : 



I. Intermediate and hind tarsi third joint longest; hind femora incrassate 

 and spinose in both sexes ; very dark in color and with a more or 

 less seneous luster R, obesa Uhler 



