184 ENTOMOLOGICAL SOCIETY 
or, zd, by the AGENCY OF MAN. A third mode of explanation, 
viz., that specifically identical specimens occurring in widely 
separated places could be the descendants of two specifically dif- 
ferent ancestors, is not longer admissible in the present state of 
Natural Science. 
As a further subdivision, the following scheme is proposed : 
I. NATURAL DISPERSION. 
a. The Circumpolar fauna. 
b. Species not belonging to the circumpolar fauna, probably of 
intratropical origin, which have spread into the temperate zone. 
c. Migratory species. 
II. DISPERSION BY THE AGENCY OF MAN. 
</. Intentional introductions. 
e. Non-intentional introductions. 
f. Non-intentional importations.* 
* Another subdivision quite different in character from those mentioned 
is, Importation by Coleopterists, or the Introduction of pinned specimens. 
This is, of course, a ridiculous division, but nevertheless it occupies quite 
a space in our descriptive literature and has occasionally assumed a rather 
serious aspect. It results from the carelessness with which exotic speci- 
mens, exchanged or purchased, are labelled and get mixed up with North 
American species, and are then either described or referred to as North 
American species. Some of our older authors made some such blun- 
ders and even our best recent authorities, here and abroad, have been 
fooled by such specimens, and this mostly without any fault of their own. 
If a big South American Dynastid beetle is offered for sale in this country 
as a North American species, as can be seen from the advertising columns 
of one of our periodicals, no one, of course, can be deceived; but when 
it comes to an obscure species of a widely-distributed genus, the case is 
quite different. Most of these spurious species have now been detected and 
eliminated from our fauna, and, as a rule, it does not make much differ- 
ence whether or not a number of them still linger in our list. In the 
course of time they all will be found out, but one or the other of them is 
liable to cause some inconvenience. As an example I mention the clover- 
leaf-weevil (Phytonomus punctatus}. Nearly ten years ago Dr. C. V. Riley 
called attention to and described the sudden appearance of this species in 
the State of New York. It turned out afterwards that Dr. LeConte had 
redescribed this European species under a different name from two old 
specimens in his collection, one coming from the Melsheimer collection, in 
