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identical with, the common English Colias Ediisa; Some moths 

 and Hymenoptera accompanied the butterflies, and a fine beetle 

 (Calosoma) flew on board. Other instances are known of this 

 beetle having been caught far out at sea, and this is the more 

 remarkable, as the greater number of the Carabidae seldom 

 or never take wing. The day had been fine and calm, and the 

 one previous to it equally so, with light and variable airs. 

 Hence we cannot suppose that the insects were blown off the 

 land, but we must conclude that they voluntarily took flight. 

 The great bands of the Colias seem at first to afford an instance 

 like those on record of the migrations of another butterfly, 

 Vanessa cardui ,- but the presence of other insects makes the 

 case distinct, and even less intelligible. Before sunset a strong 

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

 tens of thousands of the butterflies and other insects to have 

 perished. 



"On another occasion, when seventeen miles off Cape 

 Corrientes, I had a net overboard to catch pelagic animals. 

 Upon drawing it up, to my surprise, I found a considerable 

 number of beetles in it, and although in the open sea they did 

 not appear much injured by the salt water. I lost some of the 

 specimens, but those which I preserved belonged to the genera 

 Colymhetes, Hydroporus, HydroUus (two species), Notaphus, 

 Cynucus, Adimonia and Scarahmis. At first I thought that these 

 insects had been blown from the shore, but upon reflecting that 

 out of the eight species four were aquatic, and two others partly 

 so in their habits, it appeared to me most probable that they 

 were floated into the sea by a small stream which drains a lake 

 near Cape Corrientes. On any sui:)position it is an interesting 

 circumstance to find live insects swimming in the open ocean 

 seventeen miles from the nearest point of land. There are 

 several accounts of insects having been blown off the Patagonian 

 shore. Captain Cook observed it, as did more lately Captain 

 King in the ' Adventure.' The cause probably is due to the want 

 of shelter, both of trees and hills, so that an insect on the wing, 

 with an oft'-shore breeze, would be very apt to be blown out to 

 sea. The most remarkable instance I have known, of an insect 

 being caught far from the land, was that of a large grasshopper 

 {Acridinin), which flew on board when the 'Beagle' was to 

 windward of the Cape de Verd Islands, and when the nearest 



