DISTRIBUTION OF GROUSE LOCUSTS. 153 



acting iu a panicky state of excitement, the cause of this being that they 

 had darted upon the insect the author was pursuing, tumbling it over and 

 biting it savagely about the neck. The little locust finally escaped by a 

 vigorous jump. 



"According to P. R. Uhler, (1884) <77</7.v o<-uhi1nn. a true bug, is a 

 ., cious ( iKiny. 'This insect may often be seen,' says Uhler, 'in the month 

 i , .\l-iy walking about between the stones on the low banks of brooks and 



ams, where Tettijr and Batrichidea abound, watching an opportunity to 

 o c of these insects, and when the favorable moment arrives, leap- 

 ing suddenly upon one of them, clasping it with tight embrace between 

 the front femora and tibiae and then sucking out its vital juices.' Toads 

 fishes and birds also feed upon them when opportunity offers." 



The Tetrigidie arc widely distributed over the earth, many of 

 the trojm-al species having the pronotum strongly compressed 

 and bearing a resemblance to the dried leaves among which they 

 live on the ground, while some have it extremely rough, or even 

 spiny to aid in imitating their natural surroundings. In his prin- 

 cipal treatise on the group 1 1906) Hancock recognized 98 genera 

 and 4:U nominal species as known at that time. Of these 21 

 genera and 9!) species had been previously (1902) described by 

 him as inhabiting North and Central America, Mexico and the 

 West Indies. While several valid species have since been de- 

 scribed from this country, a number of those recognized by Han- 

 cock have been proven, to be mere races or varieties of the older- 

 known species, so that in the present work only seven genera, 16 

 species and eight varieties are recognized as occurring in the 

 Eastern United States and Canada. These represent but two of 

 the nine sections or subfamilies of Hancock (1900'). 



The principal literature treating especially the North Ameri- 

 can species of Tetrigida? is as follows: Bolivar, 1887; Morse. 

 1894, 1894a, 1895, 1899, 1900; Hancock. 1X96, 1898, 189Sa, 189!), 

 1900, 1902, 1906, 1909, 191S; Kehn & Hebard, 1916; Hebard, 1919. 



KEY TO EASTEUX S T T.KA MTT.IES OF TETRIGID.-'E 30 



a. Antennae with 12 to 14 joints; front femora more or less compressed 

 and carinate above; pronotum with dorsal front margin subtrun- 

 cate (Fig. 2b) rarely (Nomotettix) angulate- produced forward. 

 (Fig. Id.) I. TETRIGIN^:, p. 155. 



. Antennae with 20 or 22 joints: front femora distinctly and broadly 

 grooved or sulcate above; pronotum with front dorsal margin 

 rounded or annulate-produced over the head (Fig. 5.) 



II. BATRACTIIDIN^E, p. 179. 



30 A11 Figures below 6 cited in this key, and on the succeeding pages treating of this 

 family, refer to those of Plate II. 



