THE CANADIAN ENTOMOLOGIST. 



43 



Fig. 11. 



that we need not occupy our space with any special description. (Fig. 



ii, with the comparatively few 

 black spots, represents the male. 

 Fig. 12, the female, with its much 

 more numerous and conspicuous 

 spots and markings.) 



The chrysalis (Fig. 13, b) is over 

 half an inch in length, of a light 

 bluish-gray color, more or less pro- 

 fusely speckled with black, with the projecting portions tinted with pale 

 yellow or flesh color, and marked with large black dots. The caterpillar 

 (Fig. 13, a) varies in colour from Fi s- 12 - 



■deep to pale bluish and green ; it 

 has four longitudinal yellow stripes, 

 and is thickly covered with black 

 dots. As in the other species 

 there are two broods in the year, 

 and the winter is passed in the pupa 

 state. In the Southern States it is 

 a very injurious insect, but here it 



Plg - 13 - is too rare to be more than 



an interesting curiosity. 



Another species of Pieris 

 (P. frigida, Scudder) has 

 been taken in Labrador and 

 on the Island of Anticosti, 

 but it is not likely ever to 

 spread much, or to be ranked 

 amongst ' common insects.' 



ON THE GEOGRAPHICAL DISTRIBUTION OF SOME GENERA 



OF CANADIAN INSECTS. 



BY FRANCIS WALKER, LONDON, ENGLAND. 



Isosoma. — So much has been lately written about this genus that it 

 may be dismissed with a few words. The Ewytomidae, to which it 

 Ibelongs, were considered by Nees to be in a debatable state between the 



