A Descriptive Catalogue of the Geodephagous Coleop- 

 teba inhabiting the United States east of the Rocky Moun- 

 tains. By John L. Le Conte. Read May 25, 1846. 



The great number of works necessary in prosecuting even the 

 most simple inquiry in natural history, is often felt to be a very 

 serious inconvenience. Many, no doubt, arc deterred from entering 

 upon the study of certain departments of science by the utter im- 

 possibility of ever acquiring even a moderate knowledge of the 

 proposed subject, without the aid of a voluminous and expensive 

 library. This inconvenience is most sensibly felt by the student 

 who turns his attention to the insects of the United States : so scat- 

 tered, indeed, are the descriptions to be examined, that there is 

 scarcely a scientific society in Europe, whose transactions do not 

 contain some of our native species. It is to be regretted that col- 

 lectors have fallen into the practice of distributing large numbers 

 of apparently the same species, without first submitting them to 

 close inspection. So nearly allied are many species, in every part 

 of the globe, that even with the most accurate descriptions, it re- 

 quires much labor to identify them. An example of this may be 

 found in the genus Brachinus, of which this synopsis contains a 

 monograph. The characters are quite evident on comparing the 

 species together, but being mostly dependent on minute differ- 

 ences in form, can scarcely be expressed in a description. It hap 

 been my custom, in such cases, to lay particular stress on these 

 slight differences, by making the description in some degree com- 

 parative. A reference from one species to another is, I am aware, 

 not looked upon with a favorable eye, as it presupposes that tin 

 collection of the student is at least toleraWy extensive ; for the 

 most nearly allied species are frequently inhabitants of very different 

 regions. Still there are cases in which it was considered advis- 

 able to make such a reference, in order to avoid an absolute de- 

 scription, which would be so long and tedious as to be nearly use- 

 less. Hoping that some more attentive and industrious observer 

 may have better success in seizing on the specific characters of 



