10 PROCEEDINGS OF THE NATIONAL MUSEUM vol. no 



Brunei further inferred that Saussure's type series may have been 

 mixed, and that another included species may have caused Brunner 

 von Wattenwyl (1900, p. 257) to transfer mexicana to Dichroplus. 

 Bruner felt that Brunner must have examined Saussure's types. We 

 have not seen the material which Brunner recorded from Colombia 

 as Dichroplus mexicanus, but an error probably occurred. Scudder 

 (1897b, p. 404) listed Pezotettix mexicana as undetermined, but 

 (p. 405) he suggested that it might be the same as Melanoplus atlanis. 

 Kirby (1910, p. 513) correctly placed mexicana near atlanis RUey 

 and spretus Thomas (true spretus, though incorrectly credited to 

 Thomas), but elsewhere (p. 487) placed it ui Trigonophymus. The 

 latter placement apparently refers only to the portion of Saussure's 

 type series which Brunner associated with Colombian specimens. 

 Hebard (1917, p. 271) first brought the name mexicanus into general 

 use when he applied it to the widespread grasshoppers which we now 

 recognize as a complex, and he placed atlanis of authors in synonymy, 

 though retaining atlanis Riley for a population of eastern United 

 States and vicinity. 



Descriptive notes: A small to medium-sized member of the 

 mexicanus group. Head with dorsal carinae of vertex more prom- 

 inent and conspicuous, and closer together at anterior margins of 

 eyes than in bilituratus, especially in male; antenna about one-third 

 longer than head and pronotum combined (male), about equal to 

 combined length (female) ; a small to medium-sized mesosternal hump 

 present in male. 



Male genitalia: Cercus with extremes as illustrated (fig. 7,a), 

 usually approximating that of figure 7,a-2; furculae slender, taper- 

 ing, usually divergent, about one-third as long as supra-anal plate; 

 subgenital plate moderately upturned in lateral view, twin apices 

 (posterior view) prominent, the intervening depression rather deep 

 and well rounded; dorsal valve of aedeagus not extending dorsad 

 nearly so far as apex of aedeagus, the anterior and dorsal margin 

 covered by a light membrane, a pronounced lateral process (P of 

 fig. 3,6) borne on ventral margin, near tip of ventral valve; accessory 

 lobe large for group, larger than in bilituratus. 



Female genitalia: As illustrated (fig. 10,/,^); cercus triangular, 

 apex well rounded. 



Coloration: General color not distinctive, medium to dark for 

 group, no rich yellow specimens seen. Hind femur with four dark 

 transverse dorsal bands (including knee), inner paginal area irregu- 

 larly tinged with pinkish, followed by solid pink below, outer paginal 

 area dull brownish, paler along ventral margin and at base, ventral 

 surface deep pink; hind tibia variable, either dark pink or ashy 

 greenish gray. 



