21.-) 



even pinkish, with bluish at base; or else bluish jjfreen,apicall.v 

 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 4fi red ones were 28 males and 23 females; the 24 blue- 

 green ones, 1 1 males and 18 females, — indicating that in this spe- 

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

 Twenty specimens of «//^/^/r taken, had the tibiie 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 

 tibife. 



Thirdly, on the upper parts of the dunes, whei'e loose sand 

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

 replaced by swarms of M. (uignsfipi'/nils. This has clear blue 

 tibia?, rarely coral-red. A continuous search for examples 

 with red tibi;p in this situation yielded only two specimens, 

 both undoubted (uu/nsfijinniis. 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, M. faridiis be- 

 comes most abundant. This invariably has tibipe of a brilliant 

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



In the dense l)lack-jack oak brush which irregularly covers 

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

 of Meldiioplas are found: hirldic^, Inipudiciis, fasciatiis. and scmi- 

 ih'ri. In comparison with the four open-ground species pi'evi- 

 ously discussed, these four sheltered species confirm the gen- 

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

 is true of these species elsewliere, excepting fosciafxs, of which 

 individuals with pale green tibia: have been recorded. 



In the al)ove comparisons of species from open ground 1 

 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. 



