328 Flemiptera-Feteroptera. 
than the abdomen; legs very long, anterior coxe elongate 
and linear, two-thirds as long as the femora, which are 
slightly curved upwards towards the apex, bearing a sharp 
tooth on the lower margin just at the commencement of 
the curve, between which and the apex they are grooved 
to receive the tibia and tarsus in repose, each side of the 
groove being finely serrate, tibia and tarsus, when folded 
back, reaching to just beyond the spine, the tibia curved, 
terminating just at the spine, the tarsus very short and 
clawless. We have one of the two recorded Palearctic 
species. Dr. Puton says that the eggs have two filaments 
in this genus, 
R. linearis, Zinn.—Ochreous; pronotum constricted 
towards the middle, with the anterior margin angularly 
emarginate, sides sinuate, base twice as wide as the 
anterior margin; abdomen above red. 
L. 32-35 mm.; fil. about 28 mm. 
Rarer than Nepa, in ponds, on the bottom ; Wandsworth 
Common, Hammersmith Marshes, Douglas and Scott ; 
Earlswood, J. Linnell; Chobham, Evesham, Knowle, 
Blatch ; Norfolk, Edwards; Lee, Esher; St. Leonards, 
Guestling, Mill Hill, Middlesex, Butler ; Holywell, Cardiff, 
Billups ; Hayling Island, Wimborne, Cambridge, Du/e. 
NOTONECTIDZ, 
Convex, elytra tectiform ; head wider than the pro- 
notum, eyes large, rounded, face convex vertical, antennx 
four-jointed, rostrum short, stout at the base, conical, 
three- to four-jointed ; scutellum large ; elytra as long as 
the abdomen; anterior legs with the femora slightly 
thickened at the base, tarsi two-jointed, quite distinct from 
the tibize and articulated at their juncture, posterior legs 
with the tibia and tarsi, more especially the latter, ciliated 
in Notonecta, simple in Plea. 
