Dec, 1908.] Torre Bueno : Hemiptera Heteroptera. 233 



Family GERRID^E. 

 Subfamily Veliin.e. 



Genus Rhagovelia Mayr. 



67. R. obesa Uhl. 



White Plains. Common in streams especially such as have a surfit 

 current, from early spring to late fall. 



68. R. americana Uhl. 



White Plains. Common all the year except in winter, in springs, 

 ponds, streams, running along the banks or clinging to rocks. Hiber- 

 nates as adult. Scarsdale, Sept. 5. Portchester, Aug. 8. Found a 

 large number of winged adults in a roadside horse-trough, fed by 

 water from a spring. 



6g R. capitata Guer. 



White Plains, May 30. 



70. R. sp. { = pulchella and. for N. Am. form.) 



White Plains. This is the commonest species in the eastern 

 United States, and its white-flecked, dark-slate body is seen in every 

 pond. 



Subfamily GERRIN^. 



Genus Gerris Fabr. 



71. G. remigis Say. 



White Plains, as early as March 21, and as late as Oct. 28. Scars- 

 dale, Sept. 5. Portchester, in trough, Aug. 8. This is the common- 

 est form in the East, and is found in streams (sometimes in ponds, 

 but rarely) from early spring to late fall. 



72. G. conformis Uhl. 



White Plains, June 6 and 22; July 16 and 19; Sept. 1. This 

 species is very rare in the north, but further south, in the Carolinas, 

 appears to be nearly as common as remigis is with us. 



73. G. marginatus Say. 



White Plains. Common in ponds through the warmer portion of 

 the year. 



74. G. canaliculatus Say. 



White Plains, July 16 and 19. This is a rare form. 



75. G. rufoscutellatus Latr. 



White Plains, July 16. 



