Jassidce of Illinois. 



21 



of aiiteapical cells in the elytra, and the almost Ijasal forking of 

 the first sector. 



The remaining species group themselves into the two sub- 

 genera Diedrocephala and Tettigonia as limited by Signoret, 

 which are distinguishable by the more rounded vertex and front 

 margin of Tettigonia and the more or less conical head of 

 Diedrocephala. To Tettigonia belong T. slmilis, n. sp., T. hie- 

 roglyphica Say, and two varieties of the latter; and to Diedro- 

 cephala, T. versiitd Say, T. coccinea Forst., T. mollipes Say, and 

 T. noveboracejisisFitch. 



The relation of these species is well shown in the following 

 diagram : 



versuta. 

 coccinea. 



mollipes. 



H ^^ — " ~~' — . noveboracensis. 



tn 



"i ^ ' __ sinulis. 



^-—-"''^^■^■^ ■ 



O "^^---..^ -^^ *===r— — _ yiieroglyphica. 



O ^^^-^_ ^ ~_ ^"'^^--^ 



Z -~^.^_^ — -— ____^ \J~^ van a. 



- ~~ ^ ~- - var. b. 



bifida. 



tripunctata. 



The following synopsis will .serve to distinguish our 

 species: 



TETTIGONIA. 



Face not greatly elongate. 



Elytra with anteapical cells. 



Head more or less flat above, with the front margin 

 distinct. Subgenus I. 



But one row of anteapical cells in elytra. Sect. T. 

 Vertex with two longitudinal black lines. 



T. VERSUTA Say. 



Vertex not lineate T. coccinea Say. 



Several rows of anteapical cells. Sect. II. 



Head long, with no black spots near the tip. 



T. MOLLIPES Say. 



Head shorter, with a pair of black spots near 



the tip T. NOVEBORACENSIS Fitch. 



Head rounded at tip, with no distinct front margin. 



