THE WATER SCORPIONS. 1033 



The principal literature treating of our species is by Uhler, 

 1862, 1884; Bueno, 1903a, 1905c, 1905d, 1923; Montandon, 

 1910, 1910a, and Hungerford, 1920, 1923b. The family is a 

 small one and is represented in America by eight genera and 

 about 30 species. Of these two genera and seven species occur 

 in the eastern states. 



KEY TO EASTERN GENERA OF NEPIDvE. 



a. Form elongate-oval or elliptical, strongly flattened; front tibiae and 

 tarsi united nearly as long as femora (Subfamily Nepime). 



I. Nepa, p. 1033. 

 aa. Form elongate, subcylindrical; front tibiae and tarsi together less 

 than half the length of femora (Subfamily Ranatrinae). 



II. Ranatra, p. 1034. 



I. Nepa Linnaeus, 1758, 440. 



Elongate-oval flattened species having the head longer than 

 wide, inserted up to the eyes in a deep median concavity of the 

 front of thorax; pronotum flat, much wider than head, sub- 

 quadrate, side margins straight, front one deeply concave, hind 

 one more broadly and shallowly so ; scutellum triangular, its 

 sides nearly equal ; front legs not much shorter than the others, 

 their coxae very stout, curved, as long as head, femora much 

 swollen, grooved their full length beneath to receive the curved 

 tibiae and rigid 1-jointed tarsi, which fit into it like the blade 

 of a pocket-knife ; middle and hind femora also grooved. But 

 one American species is known. 



1174 (1379). Nepa apiculata Uhler, 1862, 12. 



Color a nearly uniform fuscous-gray; base of abdomen above tinged 

 with reddish; tarsal claws yellow. Head and pronotum granulate, the 

 latter with the transverse impression across basal third, its front portion 

 with three broad grooves separated by obtuse ridges, hind one with a 

 similar groove each side. Scutellum and claval commissure subequal in 

 length; abdominal tubes less than one-third the length of elytra. Length, 

 18—20 mm. (Fig. 207, a). 



Lake, Kosciusko and Wayne counties, Ind., May — July; prob- 

 ably occurs throughout the State, but apparently scarce as but 

 one specimen has been taken at a time. The known range ex- 

 tends from Quebec and New England west to Minnesota and 

 Illinois and south to Georgia. Of its habits Severin (1911a, 99, 

 103) has written: 



"It is found in quite shallow water, not much over two or three 

 inches deep, concealed in the mud, or in a situation where grasses grow 



