39 8 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



in size than those of the other two. The eggs in all are glued by 

 the female on the back of the male which carries them till they 

 hatch. The three Connecticut species are readily separable by 

 the following key. 



Key to Species. 



i. Tyltis not greatly produced 2 



Tylus very prominent ; body broad lutarium 



2. Exceeding 22mm. in length; body rather elongate; tylus moder- 

 ately long flumineum 



Less than 22 mm. in length ; body comparatively broad ; tylus little 

 produced testaceum 



Fig. 39. Lethocerus americanus 

 (Leidy), — dorsal view, natural size. 

 Drawing by Dr. Philip Garman. 



Fig. 40. Lethocerus americanus 

 (Leidy), — front view of head, 

 much enlarged. Drawing by Dr. 

 Philip Garman. 



B. lutarium (Stal). (PI. xix, 4.) 



Oft. Vet. Akad. Forh. xii, 190, 1855. 



This species is about the same size as flumineum Say, but very 

 easily told from it by the very prominent tylus and broad form. 

 Nothing appears to be known of its habits. 



North Guilford, 15 June, 1919 (M. P. Z.). 

 B. flumineum Say. (PL xvi, 6.) 



Het. N. Harm., 38, 1832. 



(aurantiacum Leidy. Jour. Acad. Nat. Sci. Phila. (2) i, 60, 1847.) 



This is the commonest species of the genus, and by superficial 

 characters other than those in the key, the moderately projecting 

 tylus and proportionally narrower form separate it from lutarium 

 as already noted, and its larger size from testaceum. 



This species has the same general habits as the others, but its life 

 history is known in detail. The adults hibernate buried in the 



