7IO 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY. 



[Bull. 



importance in Stal's scheme was the nature of the lateral margin 

 of the pronotum, whether keeled, expanded or plain. Still other 

 characters as noted in the keys are the presence or absence of a 

 constricted ring-like collar anteriorly on the pronotum ; the colora- 

 tion particularly of the two lobes of the pronotum which are often 

 set off from each other by a transverse constriction ; the nature of 

 the bristles or the setae on the hind tibiae ; the relative length of 



- Ocellus 



Post ocular space 



Fig. 167. Ligyrocoris diffusns Uhler, — lateral view showing structures. 

 Greatly enlarged. Drawing by Mr. H. G. Barber. 



the segments of the hind tarsi ; the armature of the fore-femora, 

 etc. In certain subfamilies, especially in the Rhyparochrominae, 

 short-winged forms (brachypterous) may frequently occur. 



The Lygaeidae as represented in the United States is relatively 

 a large family, ranking second to the largest family, Miridae. 

 Van Duzee, in his recent catalogue, lists 187 species. Most of the 

 species are relatively of small size, Oncopeltus fasciatus being the 



