215 



even pinkish, with bluish at base; or else bluish green, apically 

 yellowish or pinkish, the bluish green varying slightly towards 

 blue or green; or even yellowish. The difference between red 

 or salmon-pink, on the one hand, and the bluish to yellowish 

 tints on the other, is generally well marked. Of 70 specimens 

 of this species quite indiscriminately collected in the sand re- 

 gion, 46 had reddish tibiae, and 24 were of the blue-green or 

 yellow type — about one third of all, therefore, not being red. 

 The 46 red ones were 23 males and 23 females; the 24 blue- 

 green ones, 11 males and 13 females, — indicating that in this spe- 

 cies at least the sexes are evenly divided in this particular. 

 Twenty specimens of minor taken, had the tibia? either green- 

 ish blue or coral-red, without intergrades, 12 of these bluish 

 and 8 red. Only five of these were males, all with bluish 

 tibiae. 



Thirdly, on the upper parts of the dunes, where loose sand 

 and tufted growths begin (PI. XVIII., Fig. 1 ), these species are 

 replaced by swarms of M. angustipennis. This has clear blue 

 tibiae, rarely coral-red. A continuous search for examples 

 with red tibia? in this situation yielded only two specimens, 

 both undoubted angustipennis, one of each sex. The number of 

 this species taken was 125. Lastly, as one approaches and en- 

 ters the wind-excavated hollows of the apex, .1/. fiavidus be- 

 comes most abundant. This invariably has tibia? of a brilliant 

 and beautiful blue, approaching the shade of cobalt-blue. 



In the dense black-jack oak brush which irregularly covers 

 large areas of these sands (PI. XXI., Fig. 1), four more species 

 of Melanoplus are found: luridus, impudicus, fasciatus, and scud- 

 deri. In comparison with the four open-ground species previ- 

 ously discussed, these four sheltered species confirm the gen- 

 eral deductions, as they all invariably had red hind tibiae. This 

 is true of these species elsewhere, excepting fasciatus, of which 

 individuals with pale green tibiae have been recorded. 



In the above comparisons of species from open ground I 

 refer to the colors of local examples from the sand regions only, 

 and an examination of records of the same species for the hu- 

 mid prairie and the sand region of the foot of Lake Michigan, 



