THE CANADIAN ENTOMOLOGIST. 221 



On the way back to La Giiaira, as well as while staying there, I made 

 a careful study of the constituents of this vast throng. The most notice- 

 able fact was that practically all were males. In fact, I saw but two or 

 three females, and these were at a little roadside station, halfway between 

 the two towns. I am almost certain that these were not members of the 

 general tide, for they were flitting, to all appearance, aimlessly about, 

 and did not evince that peculiar haste to move onward so noticeable in 

 the others. 



During my stay at Caracas I collected a number of PieridsB of several 

 species, and of both sexes, in the meadows near the bank of the river 

 which flows by the city. These seemed not to be affected by the general 

 movement, and acted just as the members of the group ordinarily do. 



The most abundant species by far, making up between one-half and 

 three-quarters of the flight, was Callidryas eiibule. Of the remainder, 

 Phxbis argante was the commonest, with a close third in ApJirissa 

 statira. Here and there could be seen Callidryas philca. Once or twice 

 I thought I could make out C. cipris, but could not feel certain of the 

 identification. I make no mention, of course, of others of the group, as 

 Pontia mo7iuste and Gonepteryx clorinde, which, though common, did not 

 seem to take any part in the migration. 



A few days later, while coasting along to the port of Carupano, I 

 continually saw the butterflies singly and in little bands out over the sea. 



From Carupano I went to the island of Margarita, where I stayed for 

 over three weeks. Here it was a noticeable fact that all the Pieridre were 

 resident in the little grassy patches, in which they apparently had been 

 bred and stayed all their lives ; and here males and females were observed 

 in normal proportions. Without doubt, the island was receiving its 

 share of wanderers from the mainland, but those there showed no inclina- 

 tion to leave, and were never found outside of the restricted localities 

 where they made their homes. 



When I left the island I coasted along the shore as far as Trinidad 

 (B. W. I.), but did not observe anything of the swarms I had seen near 

 La Guaira ; and it may be mentioned here that neither about Carupano 

 nor at any part of the coast were the insects found so abundantly as at 

 and near La Guaira. 



There are two possible explanations of the facts just stated : Either 

 that this is the regular habit of these butterflies, to keep constantly moving 

 eastward during the imago state, or that it was an unusual migration. 



