56 THE ENTOMOLOGIST. 



sprung up from the north, and this must have caused tens 

 of thousands of the butterflies and other insects to have 

 perished. 



In the 'Entomologist' (vo].iii.,p.226) it is stated that during 

 a cyclone, and a distance of 600 miles from the African 

 coast and 200 miles from the Cape Verde Islands, a vessel 

 was visited by numerous birds and butterflies, the latter being 

 Diadema Bolina and Pyrameis Cardui. 



Now the instance related by Darwin only proves the fact 

 of flocks of butterflies being observed len miles from the 

 land, and that recorded in the 'Entomologist' leaves it an 

 open question as to whether the insects were direct from the 

 coast of Africa or Cape Verde Islands,* or indeed whether they 

 occurred in remarkable numbers. We have, therefore, reason 

 to believe that the vast host of Terias Lisa which arrived at 

 the Bermudas on the 1st of October last, and that visitation 

 recorded in the ' Naturalist in Bermuda' as occurring on 

 the 10th of October, 1847, are the only instances known of 

 such extraordinary flights of Lepidoptera, or indeed of any 

 insects being met with at such an amazing distance from 

 land. 



The question, therefore, naturally arises — How did this 

 immense concourse of butterflies get to the Bermudas? The 

 nearest point of land is Cape Hatteras, in North Carolina, 

 which is somewhere about 600 miles distant, and if they had 

 started from this point and taken a straight line to the islands, 

 without meeting with any contrary winds, it would, at the rate 

 of twelve miles per hour (a fair average rate of travel for any 

 of the Fieridae), have taken them two days and two hours (of 

 course including nights) to complete the distance ; a space 

 of time almost too great, we should imagine, for an insect in 

 no degree remarkable for robust frame or strength of wing to 

 keep up a continuous flight. We are, however, inclined to 

 think that the presence of this vast concourse of insects at 

 the Bermudas was not owing to ordinary causes, and that we 

 must look to some extraordinary means to solve the mystery. 

 From a very extended series of observations made at inter- 

 vals during the last twenty years, with the view of throwing 

 light upon the migration of North American birds to those 



* I do not find any record of the occurrence of P. Cardui in the Cape de 

 Verde Islands, although it is foundon the islands to the noxih.- -S.H.Scudder. 



