492. GEOGRAPHICAL DISTRIBUTION OF INSECTS. 
vicinity of the Cape, may be called the metropolis of the 
group?. On the other hand, the Rutelide and Chlamys, 
which have a range from Canada to the tropics, (within 
which is their metropolis,) are purely American groups. 
Many more might be named under this head, but these 
will suffice for examples. 
3. I call those subdominant groups, which either never 
enter the tropics, or those tropical ones whose range 
does not exceed 50° of N. L. in the old world, or 
43° in the new. I make this difference because, as 
M. Latreille observes, the southern insects which in 
Europe begin between 48° and 49° N. L., in America do 
not reach 43°. But though the winters in Canada, 
within the same parallel as France, are longer and more 
severe than those even of Great Britain or of Germany, 
yet the summers are intensely hot; so that though tropi- 
cal species do not range so high, those of a tropical s¢ruc- 
ture, as Mr. W.S. MacLeay has intimated °, may be found 
at a higher latitude in the new world than in Europe. 
The genus Melée F. affords an instance of a subdomi- 
nant group of the first description. It ranges from Swe- 
den to Spain and the shores of the Mediterranean, and 
seems a tribe almost confined to Europe, where it is not 
very unequally distributed. Of registered species Britain 
possesses the largest proportion ; but Mr. W.S. MacLeay 
is of opinion that Spain is its true metropolis?. I have 
a species of this genus, taken in North America by Pro- 
* Out of 51 species described by Bilberg, 28 are African, and 19 
of these are from the Cape. 
> Géogr. Génér. des Ins. 18. © Hor. Entomolog. 45, 
4 Dr. Leach -has described 8 British species (Linn. Trans. xi. 37.)3 
De Jean has 7 Spanish ones. 
