is* 



THE CHN AGO ACADEMY OF SCIENCES. 



Range (figure 11): Northern New England (Vermont) west to 

 Minnesota, Iowa and .Manitoba; northern Ohio, latitude 41°, north- 

 ward in British America to north latitude 57°. 



Megasoma is confined to the Canadian and Hudsonian regions 

 and the northern part of the Upper Mississippian region. It thus 

 occupies the drainage areas of the St. Lawrence River, the Mississippi 

 River and the waters of the western part of the Hudson Bay area. 

 The center of distribution is the Great Lake region, from whence the 

 species has spread to the areas east, west and north. The northward 



Fig. 14. 



extension in Keewatin was made possible by the glacial Lake Agassiz 

 via the Minnesota-Red River connection. The Ohio record is the most 

 southern. 



Megasoma is essentially a boreal species, though extending into 

 the transition life zone; the southern records in Ohio, Wisconsin and 

 Iowa are at the southernmost extension of the Alleghanian division 

 of the Transition zone, while the northern limit seems to be in the 

 Hudsonian area of the Boreal zone. The range extends through the 



