12 Annals Entomological Society of America [Vol. XIII, 



Morris gives the number of species of moths credited to the 

 North American continent, of which he had knowledge, as 1340, 

 a large number of which belonged to the Neotropical Area. 

 Barnes & McDonough, restricting themselves to Boreal Amer- 

 ica, list 7834 species as belonging to our fauna. The number of 

 species of Heterocera known to occur in Boreal America has 

 therefore since 1860 increased at least seven-fold. 



What I have stated as to the Lepidoptera is typical of what 

 has taken place in the other orders. The earliest list of beetles 

 was prepared by Melsheimer, who confined himself to those 

 species, which he knew to occur in Pennsylvania. He cat- 

 alogued 1363 species. Crotch's Check-List, published in 1873, 

 enumerated 7450 species of beetles found north of the Rio Grande 

 of Texas. The supplement to his List by Austin raised the 

 number to 9704 in the year 1880. The Revised List by Hen- 

 shaw, with the Supplements, brought the total to 11,256 in the 

 year 1895. The Catalogue by C. W. Leng, which will appear 

 shortly, is reported to bring the number of species known in 

 this faunal area up to 18,547 species, exclusive of sub-species 

 and varieties. 



The writings upon the Diptera by Osten Sacken and others, 

 which appeared about 1860, yield upon examination a total of 

 known species in this order of less than 1,000. The great 

 Catalogue prepared by our distinguished colleague. Dr. J. M. 

 Aldrich, issued in 1905, gives a total of species found on the 

 continent from the highest north to Panama of 9350. Some of 

 these species may not be valid, but most of them are, and the 

 field has only been partially explored. 



In all the other orders a similar increase in the number of 

 known species has taken place, and where at the beginning of 

 the epoch only a few hundreds of species at the most were 

 listed, we now discover that there are thousands known. 



To have prepared an approximately correct estimate of all 

 the recorded species in all the orders ascertained to be found 

 upon the soil of the United States and Canada is a labor for 

 which I have not had the necessary time. It would have 

 required the careful examination of hundreds of papers, and 

 extensive use of my adding-machine. I venture the statement, 

 however, that there are probably not far from 60,000 species 

 known, or in process of being named and described. Not more 

 than one-sixth of these were known to science fifty years ago. 



