440 GEOLOGICAL SURVEY OF THE TERRITORIES. 



will stand as distinct, and its relation to the others may be represented 



as follows : 



A. Anterior tibiae spined in front : 



a. Prosternmn spined. fThyreonotus,Pterolepis = Ehacocleis, Orelies- 



ticus.J 

 aa. Prosternum not spined : 



b. Pronotum distinctly cariued ; anterior tibife with three or 



four spines in front Becticiis, (prop.) 



1)1). Pronotum with sub-distinct lateral carinse ; anterior tibiae 

 with three spines in front; elytra not sqnamseform. 



Sub-genus Flatadeis. 



1)1)1). Pronotum without distinct lateral carinse 5 elytra squamse- 

 form : 

 G. Anterior tibise with but three or four spines in front ; 



one row Thamnotrizon. 



cc. Anterior tibite with six or eight spines in front ; two 

 rows Anahrus. 



This is rather artificial, depending too much upon a minor character, 

 but will perhaps accord with a more thorough and natural arrangement 

 when made. I have slightly expanded Fischer's spine character of 

 Decticiis. 1 am aware that Thamnotrison and Anadrushuxe been placed 

 in diiierent groups, and although I follow the arrangement in this 

 article, I confess I think the differences scarcely warrant the separation. 



A. color adus, no v. sp. 



Eather smaller than A, sim])lex or A. imrimrascens ; ovipositor shorter 

 and more curved upward. Abdomen with brown bands. 



Eyes small, round, the most angular portion being below. Pronotum. 

 rrather short ; posterior part sub-tricarinate, somewhat flattened ] apex- 

 truncate. Abdomen decticoid. Superanal plate of the female round; 

 subaual plate sub-quadrate, tumid, with a short spine at each apical angle, 

 and a short, broad spiue each side of the base. Prosternum not spined ; 

 meso- and metasteruum, with the lateral angles elevated, acute. Super- 

 anal plate of the male somewhat acute-angled; cerci with the two 

 j)rongs, mucronate, the lower ones strongly curved inward ; subanal 

 plate deeply notched; cylindrical appendages sliort. Legs slender, 

 short ; posterior femora with three or four minute abortive spines on 

 the lower exterior carina. 



Color ^ (dried after immersion in alcohol.) — Dull yellow, varied with 

 brown. Face yellow; occiput of the female brown; male pale. Disk of 

 the i^ronotum brownish, posterior portion dark ; lower margins of the 

 sides yellow. Each abdominal segment with a brown band on the base. 

 Venter' and pectus dull yellow. Elytra and wings as usual, abortive. 



Dimensions. — $, length, 1.28 inches; ijronotum, .38 inch; i)Osterior 

 femora, .08 inch ; posterior tibise, .70 inch ; ovipositor, .73 inch. $ , length, 

 1.12 inches. Eastern Colorado. 



LOCUSTINI.* 



* I follow Walker in giving this division, but I reduce it to a group, yet it does not 

 accord v<'ith my opinion as to the boundary-lines, for I really believe Tlmmnoirizon 

 should be placed in the same group as Bradijporus. But as I have not studied the 

 species of this family with sufficient care to give a satisfactory outline of the divisions, 

 I follow those of other authors. 



