PREFACE. xi 



By far the most abundant buttertly in the interior of Ecuador is 

 the Colias which has been identified by Messrs. Godman and Salvin as 

 C. dimem (p. 108) ; and exchiding one other {Pieris xcmtJiodice) its 

 individuals possibly exceed in number the individuals of all the other 

 species put together. It was collected at numerous localities between 

 7200-13,000 feet, and was seen almost everywhere within that range. 

 It was especially abiindant along the banks of streams, and was often 

 found congregated in hundreds over muddy spots or marshy soil. The 

 much less abundant Colias which has been identified as C. Icshia 

 fluttered in company with its more numerous relatives, and upon 

 several occasions the two were taken at one sweep of the net. 



The highest flying butterfly, and (with the exception of three or 

 four beetles) the highest insect of any kind obtained, barring stragglers, 

 is the Colias which is described by Messrs. Godman and Salvin as 

 C. alticola (p. 107). I have elsewhere identified it as the same species 

 which was seen upon Chimborazo by Humboldt and Bonpland.^ This 

 was actually collected between 12,000-16,000 feet, and was observed 

 slightly higher. Its highest range therefore exceeds the height of the 

 mean snow-line.^ It is scarcely possible that we can have overlooked 

 other species of diurnal Lepidoptera at the greatest altitudes ; and, in 

 the absence of others, Colias alticola must be regarded as the highest- 

 flying butterfly in either of the two Americas. 



In number of individuals, Pieris xardhodice (p. 106) is inferior only 

 to Colias dimera, and in the height which it attains it stands second to 

 Colias alticola, but its range in altitude is greater than that of eithei\ 

 It was observed in localities somewhat below 9000 feet up to a little 

 higher than 15,000 feet, and at all intermediate points. Its range 

 in altitude therefore exceeds 6000 feet, which is a larger amount 

 than was observed in the case of any other butterfly. It was moder- 

 ately abundant over the whole of the country we traversed, and was 



' See Travels amongst the Great Andes, Cliap. XIX., and the aecomiianyiiig figure. 



- The snow-line in Ecuador, as in other countries, varies upon different moun- 

 tains, and upon different sides of the same mountain. In no place should I be 

 disposed to regard it as higher than 16,000 feet. 



