1060 FAMILY XXXIX. — NOTONECTID.-E. 



elegans, a rather large black or dusky spot on the flanks of pronotum; 

 sides of pro- and mesosterna and ventrals all dark brown, shining; beak, 

 femora and hind tibiae each with a piceous stripe. Scutellum shorter 

 than in elegants, one-half the length of pronotum, male, two-thirds, female. 

 Claval orifice two-thirds the length of scutellum in both sexes. Length, 

 6.2—7 mm. (Fig. 213, a). 



Douglas Lake, Mich., Aug. 15 {Gerhard). Described from 

 Cook Co., Minn., where numerous specimens were taken by 

 Hungerford from the "amber-colored waters of a large beaver- 

 pond. Like the smaller B. elegans it swims in the shallow pro- 

 tected waters along the shore." 



1201 ( — ). Buenoa macrotibialis Hungerford, 1924a, 225. 



Sordid white, sometimes with small dark spots on sides of thorax and 

 abdomen. Eyes, as seen from the side, more convex in front and flatter 

 above than in our other species. Pronotum of both sexes with a distinct 

 median longitudinal carina, its apex projected conspicuously and acutely 

 between the eyes. Scutellum one-half as long as pronotum, male; slightly 

 shorter than pronotum, female. Male with front femora much thick- 

 ened, tibia? very broad and flat (fig. 213, d) . Length, 6.2 — 7.5 mm. 



Described from Douglas Lake, Mich., and Pelican Rapids, 

 Minn., and recorded only from those two stations. 



III. Plea Leach, 1817, 11. 



Very short, compact, strongly convex Notonectids having the 

 head subvertical, very wide between the eyes ; beak 3-jointed, 

 awl-shaped, reaching middle coxae; pronotum arched, one-half 

 wider than long, front margin truncate, hind one broadly 

 rounded ; scutellum triangular, its sides subequal, apex acute ; 

 elytra conjointly oval, strongly convex, narrowed behind, meet- 

 ing in a straight line along the dorsum, closely fitted over the 

 abdomen, membrane absent. Other characters as in generic 

 key. Two species occur in North America, both in our ter- 

 ritory. 



KEY TO EASTERN SPECIES OF PLEA. 



(/. Elytral sutures between clavus and corium usually faint or absent; 



color dull yellow without distinct fuscous marks; head with a 



reddish-brown streak between the eyes. 1202. striola. 



<ik. Elytral sutures distinct; fuscous markings prominent; head with a 



large triangular dark spot between the eyes. 1203. harnedi. 



1202 (1365). Plea striola Fieber, 1844, 18. 



Short, oval; body deeper than wide. Above grayish- or greenish- 

 yellow, shining, glabrous; eyes brown; beak and under surface dark 

 brown, pubescent. Head, pronotum and elytra coarsely, evenly, not 



