March, I9I2.] LeNG : ClCINDELID^ IN EASTERN NORTH AMERICA. 15 



except, perhaps, the similar pine barrens of Long Island, and pos- 

 sibly indicates with ritfiz'cntris the southern limit of a separate glacial 

 period. 



C. rugifrons, including modcsta, unicolor, nigrior, Carolina', 

 Iccontci, obscura, scutellaris and other unnamed varieties occurs on 

 the Atlantic Coast from Massachusetts to Key West inhabiting sandy 

 pine woods near the coast ; and, avoiding the mountains, extends 

 through the central district to Ontario and Manitoba, though much 

 modified in the various parts of its range. The occurrence of the 

 black modcsta and the green rugifrons side by side in the same region 

 is puzzling. It has been suggested that larval holes of different depth 

 would expose the pupse during the winter to different degrees of 

 cold with a possible resulting difference in color of imago. I know of 

 no proof that this is true. It may also be that the black forms and 

 green forms became separated as a result of different glacial severi- 

 ties and have been perpetuated since. This question must remain 

 unsolved until the origin of varying colors in tiger beetles is better 

 studied. 



Southern Forms. 



The species that remain are mainly of the long-legged group and 

 fall into sections according to their habitats, which may be either pine 

 woods of the coastal plain, marshes and mudflats, river banks or the 

 shore of ocean and gulf. They resemble the long-legged species of 

 the West Indies, Mexico and South America and several indeed are 

 found south of our limits as tortiiosa in West Indies, hamata in 

 Mexico, etc. They can only be regarded as emigrants from the more 

 southern countries and it is simply a matter of suitable environment 

 and accident that determines how far north each shall extend. 



Of the pine woods species, striga is confined to Florida, hirti- 

 labris reaches northern Florida, gratiosa has been found as far 

 north as Wilmington, N. C, by Messrs. Pollard and Engelhardt, 

 ahdominalis is abundant in summer north to Lakehurst, N. J., and 

 may yet be found on Long Island. The roughly sculptured form 

 scabrosa is however confined to Florida. Of the seashore species 

 dorsalis with its varieties vcnusta, saitlcyi, media and scniipicta has 

 now reached Cape Cod in Massachusetts, frequenting suitable beaches 

 all along the coast southward to Florida, around it and along the 



