Dec.,i902.] BUENO: No rONECTID.E OF ViCINITY OF NeW YORK. 231 



Characters of Sub-Families. 



I (2) Hind UUx and tarsi ciliated; abdomen with keel, hairy; eyes very 



Notonectlnse. 



large, conspicuous 



2(1) Hind t\h\x and tarsi not ciliated; abdomen neither keeled nor hairy. 

 Rostrums-jointed; eyes small, inconspicuous Pleinae. 



Sub-Family Notonectin.«. 



Geiwra. 



" Eyes not contiguous at base, posterior femora not reaching the apex of the 



h^melytra. . 



. Pronotum not exceedingly transverse ; wings present ; hemelytral area d.stmct. 



1 (2) Last segment of the antennae much shorter than penultimate ; hind tarsi 



. , , Notonecta Linn. 



without claws 



2 (i) Last segment of the antennce much longer than the penultinate. Hind 



. .^, , " Anisops 5//«. 



tarsi with claws 



Genus Notonecta. 



Species. 



1 (2-3) Base of the pronotum twice its length; sometimes only one and one 

 half times as long. (In the majority, twice as long.) Scutellum slightly shorter 



than raetanotum. • r^- t 



2 (3) Vertex five times the width of the synthlipsis uhleri Airk. 



3(2) Vertex less than five times as wide as synthlipsis. 



4(5) Lateral margins of the notocephalon nearly straight and nearly parallel. 

 Length of body not less than 13 mm. Dorsum abdominis more or less red. 



insulata IV. Kirby. 



5 (4) Lateral margins of the notocephalon more or less curved, not at all parallel. 



6 (8-10) Large robust species more than 12.5 mm. long. 



7 (9) Vertex at least three times as wide as synthlipsis. 



Head short, eyes somewhat large, lateral margins of the pronotum not quite 



. ,^ irrorata Uhler. 



slrai gh t 



8 (6-10) Small species, less than 12 mm. long. 



Pronotum twice or nearly twice as wide as long variabilis J-ieber. 



9(7) Vertex less than two and one half times as wide as synthlipsis. 



10 (6-8) Small species, subrobust. 



Base of the pronotum nearly straight unAnXaXA Say . 



Plea striola Fieb. 



Head large, wider than pronotum. Eyes small and set far apart. 



Pronotum and metanotum fused, large, about four times as large as head, and 

 overlapped at the base by the hemelytra. 



Hemelytra coriaceous throughout, with no distinction of cells ; reticulated and 

 with a setigerous puncture in each reticulation from which springs a long fine seta. 

 Strongly convex, making the body thicker through than the width. Ate absent. 

 Pedes all provided with claws ; posterior tibiae and tarsi furnished with sparse , searcely 

 noticeable, swimming cilice. 



