128 THE CANADIAN ENTOMOLOGIST 



north-western Europe and furnishes evidence of a former land connection with 

 a climate comparable to that of Britain or Ontario, in which these species lived. 



2. There are, however, in a number of cases certain more or less pro- 

 nounced differences in character between the descendants now living in Britain 

 and Canada. As a rule, the Canadian forms are smaller, and they have a shorter, 

 closer, less shaggy coat, the colour of which is not so rich or deep, but paler, 

 more dingy; brown changes to ashy grey or dingy white, and red to orange or 

 cream. Usually in the genera where white felt bands are liable to occur on the 

 abdominal segments, these bands either appear for the first time in Canadian 

 forms, or are better developed, that is to say, are wider and more extensive as 

 well as of a more extreme type, with a corresponding reduction of hair on the 

 disc of the segment. Melanism is less frequent and less pronounced. These 

 differences are so widely spread that they evidently represent a definite principle. 



3. Searching for the cause of these differences we find there is an approach 

 towards the British type of characters on the Pacific Coast and in the north 

 of Canada where the summer climate is cool as in Britain, and they are most 

 departed from in the interior and southern part where it is warm. A good illus- 

 tration of this, in addition to those already given, is found in MegachUe perihirta, 

 Ckll. a species that has no Old World representative. At Lethbridge and in 

 the Kootenays, this species has definite white felt bands on the margins of the 

 abdominal segments and there are no black hairs amongst the pale ones on the 

 apical segment. At Victoria, B. C, the white felt bands are weaker and partly 

 broken, the hairs composing them being longer and less dense, and the whole 

 coat is slightly longer. At Cochrane in Northern Ontario these bands are still 

 weaker and the hair on the apical segment is biack. 



All the species of Bombiis occurring on the Pacific Coast, in the mountains 

 of B. C. and in the Arctic, have a longer, shaggier coat than those occurring in 

 Ontario. The species of Bombiis that has the most southerly range in Canada, 

 B. pennsylvanicus has the shortest coat of all. Species oi Bombiis 'n\ the Shetland 

 Islands are rather larger and have longer, shaggier coats than the same species 

 in Scotland. In Great Britain and in Canada also, not only are the species 

 having longer and shaggier coats more plentiful in the north and west, but the 

 shorter-coated species, if they extend so far, grow longer coats. 



For the same or closely related species, size tends to become as a rule, smaller 

 in the south and interior, but the south-interior contains many species, not found 

 all over, some of which are of giant size. 



In Canada, the interior and southern conditions reach their extreme at 

 Medicine Hat, a dry, hot, basin-shaped locality in Southern Alberta. Here the 

 species of Anthophora belonging to the subgenus Amegilla, characterized by an 

 extreme development of the white felt bands and swift flight, are common. 

 Species of Amegilla are numerous in Turkistan, Central Asia. At Medicine 

 Hat species of Halidus, Colletes, Mdissodes and Melecta appear that are almost 

 covered with dust-like felt. Amongst the parasitic bees, Coelioxys ribis Ckll. 

 is common throughout Canada. In Southern Alberta is found a small form of 

 this species known as grindelics Ckll. (average length of female 10.33 mm. 

 compared with 11.66 mm. of ribis). In grindelicB not only are the white felt 

 bands on the abdomen much wider, but the face is largely covered with white 

 felt, and the white hair on the sides of the thorax inclines towards felt. At 



