of the North American Orthoptcra. 'ill 



aMgulatcd and bent inwards in Tettix, is here rounded and 

 straigliter; the lateral carinseare not so prominent as there, 

 or so strongly bent inwards in advance of the broader por- 

 tion ; the front border is thrust forward at an angle p*ar- 

 tially concealing the head; the prosternum is very strongly 

 folded transversely, forming a very deep, sharp, angulated 

 groove, which in Ti'tlix is not nearly so deep, nor are its 

 sides so nearly aj)|)roximated ; wing-covers considerably 

 longer and narrower than in Tettix. This genus further 

 dillers from Tettix in that there is a small circular swollen 

 space devoid of facets, set oil" from the upper inner border 

 of the eye. The same is true of Batrachidea, but much 

 more indistinctly, since it cannot be discovered without 

 the aid of such a lens as will readily separate the facets of 

 the eye. 



* 1. T. LATERALIS. 



Acrydium laterale, Say, Am. Ent. ; I. PI. 5. (1824.) 



" " Say, Ent. of N. Am. (ed. Le Conte) ; 



' I. 10. PL 5, figs. 2, 3. (18o9.) 



Tetrix lateralis, Harr., Cat. Ins. Mass.; 57. (1835.) 



" " Harr., Report, 3d ed. ; 187. (1862.) 



" poly morpka, var. A, Burm., Handb. d. Ent. ; II. 



659. (1838.) 



Mass., (H. Coll., Sanborn.) Maine, (Packard.) N. 

 Hampshire, (H. Coll.) Conn., (Norton.) S. Illinois, 

 (Thomas.) 



*1. T. POLYMORPHA. 



Tetrix polymorpha, var. B, Burm , Handb. d. Ent. ; II. 



659. (1838.) 



Tetrix parvipennis, Harr., Cat. Ins. Mass,; 57. (1835.) 



" " Harr., Report, 3d ed. ; 187, fig. 82. 



(1862.) 



In this species the wings are almost abortive, and the 



pronotum extends only to the tip of the abdomen, while 



in T. lateralis the wings extend beyond the pronotum, 



