TILE CANADIAN ENTOMOLOGIST. 23 



type of a North American moth descended from a pre-Glacial North 

 American ancestor. I have taken Datana as an example of a North 

 American moth which has become so modified from its original source 

 as a member of the ancient circumpolar fauna, the first element in our 

 present North American fauna, as to be now classed as North American. 

 In the same group I take Apatelodes as an example of a North American 

 moth which has become so modified from its original source as a member 

 of the tropical, or South American fauna, as to be now classed as North 

 American. The Ceratocampince., the genus Hyperchi7-ia, I regard as 

 ultimately of Southern origin. The genus Catocala belongs to the first 

 element in our fauna ; it is a development from a former circumpolar 

 fauna. 



But not to go further for the moment in this direction, let u? compare 

 the American and European butterflies and moths in a more general way, 

 so as to arrive at some conclusion with regard to the departure from a 

 common type in the members of the circumpolar fauna. The first thing 

 which strikes us is the comparatively greater tendency to variation, to 

 splitting into species which characterizes the North American butterflies 

 and moths. Take the genus Colias, which belongs to the first element in 

 our fauna; how it wanders into distinct forms, sometimes still connected, 

 again no longer now members of the same reproductive cycle. Without 

 Mr. W. H. Edwards's observations on the larva, we should be quite at sea. 



But now, compare our protean Colias species with the two set Euro- 

 pean forms ! What is true of Colias is true in other genera. Take the 

 genus Datana among the moths ; this is an American out-growth of the 

 European Phalera. Now in Europe there are two closely allied forms of 

 F/ialera, bucephala and bucephaloides, but they are to be at once 

 picked out by a slight but constant difference. In America we have 

 six or seven species of Datana, and, if we take out Angusii zxvA perspicua., 

 as being distinguishable by general colour, all very near and difficult to dis- 

 tinguish as moths. In the genus Clisiocainpa, the same phenomena are 

 repeated. See how variable the underwings are and how much difference 

 of opinion exists among writers ! I am of opinion that Catocala residua 

 is a good species, but Mr. Hulst is not with me here. At the best we can 

 say, that Mr. Hulst, in regard to other species and varieties (e. g. prceclara, 

 herodias, gisela), has corrected himself and adopted my views, and that he 

 will also probably come in time to agree with me in regard to Alabamce, 



