662 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



G. (Gerris) canaliculatus Say. 



Het. New Harm., 36, 1832; Compl. Writings, i, 363, 1859. 



This form is rather rare in the North, where it frequents still 

 ponds sheltered in secluded little coves and bays. Like all the 

 others, it has five nymphal stages. 



Hamden, 24 Oct., 1910; New Haven, 4 May, 191 1 (B. H. W.). 



As the subgenera Limnogonus (hesione) and Limnoporus 

 (rufoscutellatus) have each but the one indicated species in our 

 territory, they are easily separated by the preceding table. 

 G. (Limnoporus) rufoscutellatus Latreille. (PI. xvi, 10.) 



Gen. Crust. Ins., iii, 134, 1807. 



This universal Gerrid, of whose habits little is known, is a 

 dweller in still waters. It is rarely found wingless. In the East 

 it occurs as far south as North Carolina ; it is also found in the 

 West and in Northern Europe and Asia. 



New Haven, 28 Apr., 4, 15 May, 1911 (B. H. W.) ; Cornwall, 10 Aug., 

 1918 (B. H. W.). 



G. (Limnogonus) hesione Kirkaldy. 



The Entomologist, xxxv, 137, 1902. 



This species has been taken in abundance in Ohio and it may 

 finally be found in Connecticut. 



Tribe HALOBATINI. 



Key to Genera. 



1. First antennal joint much shorter than the other three taken to- 



gether, not much longer than the second and third taken together, 



and sometimes shorter 2 



First antennal joint nearly equal to the remaining three taken to- 

 gether, much longer than the second and third taken together, 

 almost as long as the entire body ; hind femora twice as long as 

 hind tibiae Metrobates, p. 662 



2. Apical joint of antennae (fourth) longer than third 3 



Apical joint of antennae (fourth) never more than equal to third; 



basal joint of anterior tarsi much shorter than second; hind 

 femora equal to or much shorter than hind tibia and tarsus taken 

 together Rheumatobates, p. 663 



3. Eyes large, fairly prominent; colors black and yellow; lacustrine 



species Trepobates, p. 663 



Eyes small, widely separated ; plumbeous forms, entirely sericeous ; 

 oceanic species Halobates, p. 663 



Metrobates Uhler. 



M. hesperius Uhler. 



Proc. Bost. Soc. Nat. Hist, xiv, 109, 1871 : xix, 438, 1878. 



A lacustrine species which congregates in large patches of black- 

 ness on the smooth waters of our lakes. It is very active and skips 

 and jumps about. Found from Canada to North Carolina. It is 

 found both winged and wingless. 



Portland, 15 Aug., 1913 (B. H. W.). 



