15 
HOW TO OBTAIN ENTOMOLOGICAL BOOKS AND PAMPHLETS. 
Comparatively few of the works treating of the classification of North 
American insects have been published as separate books; but such as 
have been so published, if of comparatively recent date, can be obtained 
through the regular book trade. By far the greater number of the 
monographs and synopses mentioned in the preceding pages have 
been published in scientific periodicals and transactions of scientific 
societies. Thse periodicals and transactions can be obtained through 
the societies which publish them and through the publishers; but, 
in the case of transactions, single volumes, and more especially single 
papers, are seldom sold, and the older volumes are liable to be out 
of print. Moreover the expense attending the purchase of all of the 
periodicals containing the publications on a given order of insects will 
be so great as to put them beyond the reach of most entomologists. 
The custom of placing at the disposal of authors a number of separate 
copies of their papers overcomes this difficulty to some extent and cre- 
ates a small supply. Thus it often happens that a person interested 
ean obtain a copy of a scientific paper by addressing the author person- 
ally. Many of these separate copies also get into the possession of 
dealers in second-hand books, and can be purchased from them. The 
American Entomological Society of Philadelphia and also a few other 
societies here and in Europe offer for sale from their duplicates many 
of these authors’ extras, and in some cases publish lists. There are, 
moreover, certain business establishments which make a specialty of 
the sale of works and pamphlets on Natural History, including Ento- © 
mology, and it is chiefly through such establishments that the student 
is enabled to secure the larger portion of the works needed. In Amer- 
ica there is at present but one of these special dealers of any promi- 
nence, viz, Dr. A. E. Foote, of 1223 Belmont avenue, Philadelphia, Pa. 
But in Europe there are several of considerable reputation; among these 
we may mention: : 
R. Friedlaender & Sohn, Carlstrasse, 11, Berlin, Germany. 
Ed. André, 21 Boulevard Bretonniere, Beaune (Céte-d’Or), France. 
'H. W. Schmidt, Rannische Strasse, Nr. 1, Halle a. S, Germany. 
J.B. Bailliére et fils, 19, Rue Hautefeuille, Paris, France. 
Oswald Weigel, Kénigsstrasse, 1, Leipzig, Germany. 
U. Hoepli, Corso Vitt. Eman., 37, Milan, Italy. 
Otto Harrassowitz, Querstrasse, 14, Leipzig, Germany. 
William Wesley & Son, 28 Essex street, Strand, London, England. 
All of these firms publish catalogues, and in writing to them the ento- 
mological catalogue should be especially asked for. There are two firms 
in New York which act as agents for all of these houses, and works can 
be ordered through them or catalogues obtained from them. These are 
