4 ENTOMOLOGICAL NEWS. [J^n- 



pale rufous, testaceous, orange or yellow,* through browns and 

 rufous-browns to dark brown and black. The body is often darker 

 than the legs, and the elytra of beetles are often darker than the 

 thorax, though the reverse of this latter condition occurs in Coc- 

 cinella, Lacnaa, Dermestes, etc. 



Metallic colors seem to have their beginning at either end of 

 the series, but it would seem that, whereas testaceous insects vary 

 to metallic yellows and yellowish greens, black insects vary to blue. 

 If black is highest in the non-metallic series, so we might expect 

 that blue, to which it varies, would be higher than yellow or green 

 in the metallic series, and this, I believe, is precisely the case. 

 Harpalus oenetis is sometimes dull and sometimes metallic green, 

 or coppery. The green form, being the commonest, is regarded 

 as the type, but no doubt the dull variety is the oldest, and the 

 green the newest, or highest. The dull forms, then, are atavisms. 

 The same sort of thing occurs in Meligethes rufipes, and a speci- 

 men was even found (Ent. Mo. Mag. 1885, p. 217) with one ely- 

 tron dull reddish, and the other with a slight greenish metallic 

 tinge. This case of partial or unilateral atavism is not unique. 

 I have recorded a parallel case, though not relating to metallic 

 colors, in Dermestes fasciatus (Kntoxn. 1889, p. 119). 



Trirhabda convergens has a variety which I call virescens, 

 common at West Cliff, Col. , in which the elytra, except a yellow 

 costal or outer border, are rather dull metallic green. Here we 

 see the tendency of the edges of the elytra to keep the original 

 color, a very common thing with many beetles, and often a fixed 

 specific character. 



Dark species in the genus Longitarsus sometimes tend to be- 

 come bronzed. Crepidodera longula, as described by Dr. Horn, 

 is rufo-testaceous, with a greenish lustre. These are the beginnings 

 of metallic colors at the lower end of the series. The paler the 

 non-metallic form, the yellower its metallic variety, and here I am 

 assuming that all metallic forms were once varieties. 



In Haltica we have beautiful series of variations and changes 

 from metallic golden to blue. From the distribution gi\en 

 by Dr. Horn (Trans. Am. Ent. Soc. 1889, p. 219, et seg.) it 

 would appear that golden, green and bronzy forms are more 



* And the yellow varying and changing, as it does throughout organic 

 nature, to scarlet, but this is beside our present purpose. 



