March, I9I2.] LeNG : CiCINDELID.E IN EASTERN NoRTH AMERICA. 13 



to the mountains of Georgia; as transversa it occurs in the same 

 Georgia mountains and elsewhere in the south; in Maine it has de- 

 veloped a special form called sprcta. Westward it has split into 

 many more varieties, of which most resemble the variety transversa 

 more than typical purpurea, with the Pacific forms as usual more 

 differentiated and more like the related old world species. Assuming 

 an original circumpolar stock of which the Pacific branch retained the 

 greater resemblance to the Siberian, while the Atlantic reseml^led the 

 present transversa, all driven southward during the ice age, the 

 Pacific branch would become isolated by the Sierra Nevada and 

 develop the present Pacific forms, while the x-Xtlantic form would 

 survive in the most southerly point to which it was driven during the 

 ice age, possibly the mountains of Georgia, spreading thence north- 

 east and northwest and developing in the changing climates it reached 

 the forms we now have. All the time the task of splitting the whole 

 mass into isolated groups is being accomplished by the alternating 

 northward and southward motion of the glacier's front. Extermina- 

 tion would be the result if the species, demanding as it does, only 

 a sloping soil for its breeding place, were not adaptable to the last 

 degree. That it is so is evident from the variety of climates in which 

 it lives as well as from the recorded breeding places, sometimes 

 grassy, sometimes bare, but always sloping ground. The especially 

 remarkable feature is the great number of varieties, so great that 

 many have never been named, the result I believe of the capacity 

 each colony, isolated by glacial action, has possessed of adapting itself 

 to local environment and perpetuating a modified form of the original 

 stock. 



C. repanda and C. hirticollis are also species which are almost 

 reproduced in old world species ; hirticollis extending from Maine to 

 Florida on the Atlantic Coast and westward to California and Mexico. 

 On Long Island and in Rhode Island the indistinctly marked form 

 called nigrita by Abbott Davis occurs and in the southwest the 

 Mexican ponderosa, almost indistinguishable, occurs; repanda also 

 extends from Canada to Florida and spreads westward to almost every 

 state in the union w'thout important modifications even in color. 

 Mr. Harris sees in these species, especially repanda. very ancient 

 forms of Cicindcla and, I may add, adaptable to various environ- 

 ments, which have interbred for so long a time that all the specimens 

 reach an established neutral character. 



