4 Journal New York Entomological Society. ['^'o'- ^^• 



the specimens have heen inserted in the zone within which they occur 

 in nature. Each vertical line of specimens contains one species. At a 

 glance you perceive how few species penetrate the boreal zone, indi- 

 cating perhaps the inability of the others to live under its cold condi- 

 tions ; but you will also observe that the bulk of our species occur in 

 several zones. Not always however without some modification in the 

 different zones. Compare the dark i2-guttata of Lakehurst, N. J., 

 with the bright green specimen from Cape Breton, or the little dorsalis 

 of Florida with the much larger specimen from Massachusetts, and 

 you will realize the modifications that do occur. The most marked 

 example is in tranqucbarica and here the forms due apparently to 

 climatic differences have received varietal names, the southernmost 

 form being called viilgaris->iiiiior, reduced in size and dark with 

 narrow lines, the northernmost, horicoucnsis, large, brilliant metallic, 

 with broad lines. Again in repanda and pnnctulata you see instances 

 of the contrary where the species unmodified live in several zones. 

 Thus it is evident that the influence of temperature in controlling dis- 

 tribution and in modifying color is one of the factors but not the 

 absolute and only factor. 



Akin to temperature as controlled by latitude is temperature as 

 controlled by elevation, but as the mountain slopes which produce the 

 latter also introduce other conditions, the dift'erences that have been 

 observed between lowland and mountain forms of the same species 

 cannot be surely ascribed to temperature. The modification of 6- 

 guttata described as harrisi, the modification of longilahris described 

 as oslari. and other similar modifications apparently resulting from 

 elevation can only be doubtfully referred to the influence of colder 

 temperature ; it may however be significant that a more brilliant color 

 results equally from high latitude and high elevation. An interesting 

 case, when sufficiently confirmed, may be found in longilahris in 

 Newfoundland, which near the sea-level is dark bronze, but in the 

 tnountains of the west coast, as indicated by three specimens only, is 

 bright green. 



Lccontc's Districts. — Leaving the question of temperature and 

 latitude and the Merriam zones, all of which on the Atlantic coast 

 mainly control distribution north and south, let us consider the ideas 

 of Dr. Leconte, which while they did not disregard the evidently 

 boreal character of many species and the southern limit to the distri- 



