188 ENTOMOLOGICAL SOCIETY 
coast strip of southern Florida and an apparently less defined 
zone along the Mexican boundary. 
MIGRATORY SPECIES. There are very few migratory insects 
anyhow, and none among the Coleoptera, and I may therefore 
dismiss the subject with the remark that the occasional movements 
reported among Coleoptera I refer more particularly to certain 
apparently migratory swarms of Carabidas observed in temperate 
South America are always on a comparatively small scale, never 
extending from one faunal region to another, and that they are not 
comparable to the real migrations among certain species of Lepi- 
doptera and Orthoptera. 
DISPERSION BY THE AGENCY OF MAN. The second class of 
species common to our own and other faunal regions comprises 
those which have been or are being carried from one continent to 
another by the agency of man a vast number of species which 
were not distributed over portions of the New and Old World 
before the discovery of America, now nearly 400 years ago. At 
the first glance the subject appears to be a very simple one. We 
should expect that, with the increase of our marine intercourse, 
with the shortening of the steamer trips between all ports of the 
whole world, there should be going on an ever-increasing inter- 
change of the faunas and floras of the continents. We should fur- 
ther expect this intercourse to be rriost marked between those 
continents which lie under the same degrees of latitude of the same 
hemisphere and enjoy the same or nearly the same climate e. g., 
between Europe and North America ; this interchange to be less 
marked between countries which, although situated under the same 
latitude, show differences in climatic conditions e. g., between 
our Pacific coast, more especially California, and Japan or China ; 
this interchange to be much smaller if importation involve a de- 
cided change of climate, as between any intratropical country and 
North America, or between the temperate zone of the southern 
hemisphere, through the tropics, into the temperate zone of the 
northern hemisphere. All this is supported by facts, but a glance 
at the list of species at once shows that there does not exist an in- 
terchange between the faunas of the Old and New World, but 
only an introduction of Old World forms into North America, 
while North America has, with very few exceptions, never ex- 
ported any of her native species. This phenomenon has long 
