980 FAMILY XXXI. — GERRID^E. 



Kosciusko Co., Ind., Aug. 27 ; taken in company with Gerris 

 marginatus in a bay of Tippecanoe Lake. Dunedin and R. P. 

 Park, Fla., Nov. 27 — April 25 ; mating on the latter date 

 (W.S.B.). Lake Okeechobee, Fla., April (Paris). Recorded 

 heretofore from Ohio, Michigan, Kansas, Daytona, Fla., and 

 Panama. About Dunedin it is frequent in several lakes, the 

 winged form almost as abundant as the wingless. When dis- 

 turbed it often leaps a foot or more several times in succession. 

 In Ohio Drake found the apterous form very common in Sep- 

 tember and October in ponds near Columbus. He states that : 

 "It seems to be distinctly a lacustrine species and found almost 

 entirely in the apterous form. They are very active little 

 creatures and congregate in immense numbers near the shore 

 in sheltered places." 



III. Metrobates Uhler, 1871, 108. 



Short-bodied, robust, opaque species, the brachypterous form 

 having the head broader across eyes than long, much narrower 

 than mesonotum; eyes very large, coarsely granulated, pro- 

 jecting widely over the sides of pronotum ; beak stout, hairy, 

 reaching mesosternum ; pronotum wider than long, narrower 

 than head, concave at middle ; mesonotum very large, subquad- 

 rate, its disk with a wide shallow median impression ; abdomen 

 short, declivent, its margins reflexed ; front legs short, joint 1 of 

 tarsi only about one-fourth the length of 2 ; middle and hind 

 legs very long, the middle femora stouter than and about two- 

 thirds the length of hind ones; hind tibiae and tarsi united only 

 as long as middle tarsi. Macropterous form with hind lobe of 

 pronotum extending back in the form of a broad triangle with 

 sides nearly straight and tip narrowly rounded ; elytra longer 

 than abdomen, the nervures prominent and membrane more 

 than twice as long as corium. But one species is known. 



1119 (1295). Metrobates hesperius Uhler, 1871, 109. 



Brachypterous form velvety black, opaque, densely clothed with a 

 very short velvety pile and, in fresh specimens, with a leaden bloom 

 which forms a wide median and two lateral stripes on mesonotum, covers 

 the greater part of dorsum of abdomen and the whole under surface; 

 base of first antennal, an interocular bilobed spot and a median spot in 

 depression of pronotum, usually dull reddish-yellow; antennae and legs 

 dark brown, the coxae yellow beneath. Nymphs with a median stripe 

 along the dorsal groove, two spots each side of mesonotum, the middle of 

 dorsals 3 — 6 and the greater part of under surface bright yellow. An- 

 tenna? almost as long as body, joint 1 gradually thickened from the base, 



