392 FAMILY VI. ACRIDID/E. THE LOCUSTS. 



Four species and two varieties of the group occur in our terri- 

 tory, two of them with extended range, the others confined to the 

 southern coastwise states. 



Fig. 136. a, Outline of tegnien of female of M. scudderi; b, outline of male cercus of 

 same; c, same of M. carncgici, e, same of M. quercicola; d, side view of apex of male 

 abdomen of M. dawsoni . (After Morse and R. & H.) 



KEY TO EASTERN SPECIES OF SCUDDERI GROUP. 



a. General color grayish- or dark reddish-brown; size smaller, the males 



not over IS. 5 mm. 



b. Furcula nearly half the length of the supra-anal plate (Fig. 137) ; 

 prozona as broad as or broader than long; tegmina ovate-lanceo- 

 late, subcuminate, slightly longer than pronotum (rarely fully 

 developed.) 182. DAWSONI. 



bb. Furcula very short or wanting, when present scarcely half the 

 length of the last dorsal segment (PI. Ill, b) ; prozona longer 

 than broad. 



c. Tegmina as long as or slightly longer than pronotum, their 

 tips subacuminate; cerci subfalcate, their rounded tips about 

 half as broad as base (Fig. 136, a, b.) 183. SCUDDERI. 



cc. Tegmina shorter than pronotum, their tips narrowly rounded; 

 cerci shorter, triangular, their tips less than one-fourth as 

 broad as base (Fig. 136, c.) 



d. Cerci rather broadly triangular, tapering evenly from base to 

 apex; furcula short finger-like or triangular projections 

 lying on the bases of the median ridges. 184. CARNEGIEI. 

 d(L Cerci elongate-triangular, tapering from base to middle, the 

 apical half very narrow, of nearly equal width throughout; 

 furcula represented only by swollen convexities of the mar- 

 gins of median notch of last dorsal segment. 



184a. ACIDOCERCUS. 

 aa. General color pale reddish-yellow or ochraceous-tawny; larger, males 



19 or more mm. in length. 



e. Tegmina broadly oval with tips feebly truncate the females with 

 dorsal and lateral fields slightly but obvously defined; cercus 

 a triangular plate, slightly less than twice as long as its basal 

 width, its apical fourth not incurved. 185. DAVISI. M 



ee. Tegmina oval, their tips rounded and dorsal and lateral fields 

 not defined; cercus more slender, slightly over twice as long as 

 its basal width, its apical fourth much narrower and curved 

 inward (Fig. 136, e.) 185a. QUERCicoLA. 66 



56 These two forms were placed by Hebard in the genus Eotctti.v, he stating (1918, 

 153) that "in general appearance these insects suggest rather strongly a very large and 

 exceedingly smooth development of the Scudderi group of the genus Mclanoplus. The 

 general structure, however, satisfies us that they must be assigned to Eotettix." Now the 

 principal structural characters of the genus Eotcttir as given by Scudder, its founder 

 (18973, n), are the presence of a distinct subapical tubercle on subgenital plate of male, 

 a sharply acuminate prosternal spine, distinctly developed furcula and styliform cerci, all 

 of which characters fail in davisi and quercicola. I have, therefore, placed them in this 

 series of Mclanoplus. 



