I N T II D U C T 1 i\ . 



THE present memoir is intended to give a catalogue of the Coleoptera thus far 

 known to inhabit the middle eastern portion of the great central region of tem- 

 perate North America. The boundaries of the province here treated of are as 

 follows: north by the Missouri river, east by the meridian of the mouth of the 

 Kansas or Platte river, south by about latitude 34, and west by the main mass 

 of the Rocky mountains. 



It thus includes Kansas, a portion of Nebraska, and the eastern part of New 

 Mexico. The eastern limit of this province is well denned ; the other boundaries 

 are indefinite, since it there fades imperceptibly into other provinces of the same 

 great zoological district. 



Before proceeding to consider the special material used in the preparation of this 

 memoir, it will be proper to give a short sketch of the general results thus far 

 obtained regarding the geographical distribution of Coleopterous insects in the 

 territory of our republic. 



The whole region of the United States is divided by meridional, or nearly meri- 

 dional lines into three, or perhaps four, great zoological districts, distinguished each 

 by numerous peculiar genera and species, which, with but few exceptions, do not 

 extend into the contiguous districts. The eastern one of these extends from the 

 Atlantic Ocean to the arid prairies on the west of Iowa, Missouri, and Arkansas, 

 thus embracing (for convenience merely) a narrow strip near the sea-coast of 

 Texas. This narrow strip, however, belongs more properly to the eastern province 

 of the tropical zoological district of Mexico. 



The central district extends from the western limit of the eastern district, per- 

 haps to the mass of the Sierra Nevada of California, including Kansas, Nebraska, 

 Utah, New Mexico, Arizona, and Texas. Except Arizona, the entomological fauna 

 of the portion of this district west of the Rocky mountains, and in fact that of the 

 mountain region proper, is entirely unknown ; and it is very probable that the 

 region does in reality constitute two districts bounded by the Rocky mountains, and 

 southern continuation thereof. 



The western district is the maritime slope of the continent to the Pacific, and 

 thus includes California, Oregon, and Washington territories. 



These great districts are divided into a number of provinces, of unequal size, and 

 which are limited by changes in climate, and therefore sometimes distinctly, some- 

 times vaguely defined. 



The Atlantic district may be divided into: 1, a northern province, including 

 Maine, Eastern Canada, Nova Scotia, Newfoundland, etc., and extending west- 



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