14 Journal New York Entomological Society. [Vol. xx. 



C. tranqucbarica, which on the Atlantic Coast extends from New- 

 foundland to Florida and westward across the continent presents a 

 parallel case, minus the enormous development of varieties. South- 

 ward this species becomes dark, small, faintly marked, var. vulgaris- 

 minor, northward brilliant, large, broadly marked, var. horiconcnsis, 

 northwesterly it becomes obliquata and in the Sierra Nevada it meets 

 the fate of other species and splits into varieties of which some are 

 still unnamed. Its history is similar to that outlined for purpurea 

 but breeding in a variety of flat sandy places, it has followed the 

 broad plains and isolation has been less potent. 



Second Group. 



C. gcncrosa is a species which does not occur in the boreal zone 

 nor in the lower austral, which has no near relatives in the old world 

 nor in South America, with a distribution extending from southern 

 New Hampshire through Massachusetts, Connecticut, New York and 

 New Jersey, across the mountains in West Virginia, Ohio, Indiana 

 and Illinois, thence running northwest to Manitoba, where a variety 

 is developed and southwest to northern Texas developing another 

 variety. As already pointed out a third variety unnamed is made by 

 our eastern specimens. I cannot see anything in this history but a 

 species indigenous to the region it now inhabits driven southward by 

 the glacier but returning later to its old haunts, without a capacity for 

 adapting itself to colder regions; otherwise it would accompany 

 tranqneharica, further north and south than it actually does. C. 

 Icpida, C. ancocisconcnsts, C. marginipennis, C. rnfivenfris are also 

 parallel cases but complicated by the rigorous requirements of the 

 species in choosing breeding places so that they have failed to spread 

 as widely from the post-glacial colonies of survivors. 



C. 6-guttata again parallels the story of gcncrosa and it remained 

 for Casey to point out the constant difference in punctuation between 

 eastern and western specimens (compare tridcns Csy.). 



C. patruela and C. unipunctata present no points of difference 

 except that their abundance in the mountains of Georgia again points 

 to that locality as the latitude to which glacier-driven species reached 

 in their southward movement ; patruela has a variety consentanea in 

 the New Jersey pine barrens that occurs nowhere else in abundance, 



