SUPERFAMILY GERROIDEvE. 967 



sisting of the juices of insects that fall into the water and the number of 

 these is considerable along the grassy aquatic borders. When such a 

 hapless insect falls it is at once pounced upon by one or several of these 

 voracious bugs, who insert their beaks and proceed to suck the juices 

 from their still struggling victim. I have seen no less than ten thus 

 surround their prey all with their heads in the direction of common 

 interest and their bodies radiating outward." 



1105 (1282). Hydrometra australis Say, 1832, 35; I, 361. 



Differs from martini chiefly in characters given in key. General 

 color darker, being more often a bluish-black. Front portion of head 

 proportionally longer and more dilated towards tip. Last dorsal of male 

 less swollen and bearing a short tubercle instead of a spine. Tip of 

 abdomen of females less elongate than in martini. Length, 8 — 11 mm. 



Dunedin, Fla., April 23 ; three specimens taken from a mass 

 of decaying weeds on margin of Jerry Lake. Recorded from 

 Jacksonville by Barber. Its known range extends from White 

 Plains, N. Y., southwest to Georgia and Florida and west to 

 Kansas and Louisiana. Appears to be much less common than 

 martini though probably confused with it in many collections. 



Superfamily GERROIDE^E Reuter, 1912b, 15, 48. 



This superfamily, as limited in the key, p. 34, comprises 

 elongate, rather slender semi-aquatic species having the anten- 

 nae exposed, as long as or longer than head, the latter shorter 

 than pronotum, including scutellum ; beak 4-jointed ; elytra 

 usually dimorphic, when present largely membranous, the usual 

 divisions not differentiated, the veins longitudinal, forming dis- 

 tinct cells; osteola present; last tarsal joint bifid at apex, its 

 claws inserted on the side some distance above the tip (fig. 

 6,»). 



The superfamily as thus characterized contains two families, 

 both represented in our territory. 



KEY TO FAMILIES OF GERROIDE^E. 



a. Hind femora much surpassing apex of abdomen; middle and hind 

 coxae approximate, distant from front ones. 



Family XXXI. Gerrid^e, p. 967. 



««. Hind femora but little if at all surpassing tip of abdomen; middle 



coxae (except in Rhagovelia) equally distant from front and hind 



ones. Family XXXII. Veliid.-e, p. 987. 



Family XXXI. GERRID^ Amyot & Serville, 1843, 410. 



The Wherrymen or Water Striders. 



This family comprises semi-aquatic Heteroptera of medium 

 size having the body usually narrow, elongate, widest behind 



