;>*<} 



from S,()00 or 9,000 feet to about 11,000 feet, or the " timber-line" — i.e., the 

 limits of trees. They are subalpine and circumpolar species, and some also 

 occur in the highlands of North Temperate America and Europe-Asia. 



Glaucoptervxea-siata. ... 

 Epirrita cambricaria .. . . 



Epirritadilntata 



Hydriomena trifasciata. . 

 Petrophora truncata . ... 

 Petrophora pruuata vars 



Petrophora populata 



Petrophora testata 



Ochyria ferrugaria 



Ochyria muuitaria 



Rheurnaptera fluctuata. . 

 Rbeumaptera lugubrata . 

 Rbeumaptera tristata . . . 

 Rbeumaptera hastata ... 



Though P. testata and R. lugubrata have not occurred on Mount Wash- 

 ington, it is found in other parts of New England. We ma)- also expect to 

 find Epirrita dilutata in Colorado and the Pacific coast, as it is common in 

 Newfoundland and occurs in Labrador and Canada, and will probably be 

 found in the highlands of New England. 



This table indicates how wide are the limits of distribution of these 

 species, and it will be seen how important it is to follow circumpolar and 

 north-temperate insect-faunae around the globe, from continent to continent. 

 It will then be seen how inadequate must be our views regarding the geo- 

 graphical distribution of the animals and plants of our own continent, without 

 specimens from similar regions in the same zones in the Old World. It will 

 be found that for the study of the insect-fauna of the Rocky Mountains and 

 Pacific coast we must have ample collections from the Ural and Altai 

 Mountains and surrounding plateaus, while a study of the Japanese and 

 Hindoo-Chinese fauna; must accompany examinations of the species of the 

 Atlantic fauna; just as we are obliged, while examining the Atlantic fauna, 



