Nepide. 329 
NOTONECTA, Linn. 
Head broad, eyes large, vertex not half so wide as either 
eye, rostrum four-jointed; pronotum trapeziform, trans- 
verse, very convex, anterior margin slightly produced in 
the centre, sides straight, base shehtly produced and 
rounded near the angles; scutellum almost as wide as 
the pronotum, and nearly equilateral; elytra more than 
twice as long as wide, pointed, membrane distinct ; 
abdomen ciliated at the sides and apex, carinated and 
ciliated along the centre beneath; sterna with golden 
hairs; all the tarsi two-jointed, posterior pair with long 
ciliz, intermediate femora with a sharp tooth near the 
apex. There are two European species, of which only one 
has occurred in this country; the insects swim on their 
backs, and they are capable of biting with some severity. 
N. glauca, Linn. (var. maculata, Fab.)—Head and 
pronotum shining, ochreous white, or ochreous, the latter 
generally with a dark band across the base ; scutellum dull, 
black ; elytra ochreous, with a row of black spots along 
the lateral margins, or (var. furcata) bluish black, with two 
elongate spots at the base, or (var. maculata) reddish 
ochreous, irrorated with black or brown spots; legs pale 
ochreous, or greenish ; abdomen black. 
L. 15 mm. 
Common and generally distributed, the ordinary “ water 
boatman” of our ponds; var. maculata rarer. 
PLEA, Leach. 
Minute, not twice as long as wide. Head broad, eyes 
remote, vertex twice as wide as either eye, rostrum three- 
jointed; pronotum rounded in front, sides very short, 
base largely produced and rounded ; scutellum narrow, tri- 
angular ; elytra short, very declivous posteriorly, without 
distinct membrane, a small portion of each elytron is sepa- 
rated off by a suture close to the exterior basal angle (this 
