26 REPORT OF THE SECRETARY. 



of the barometer is less in summer than in winter, is prominently 

 exhibited. 



The mean height of the barometer for the whole time was 29.7T5 

 inches, which is less than that for places under the tropics; and it 

 should be stated that Van Rensselaer harbor is fourteen degrees 

 farther north than the latitude 04° in which the height of the 

 barometer is a minimum. 



The fluctuations in the height of the barometer were greater in 

 winter than in summer. The greatest pressure, 30.97 inches, oc- 

 curred in the morning of January 22, 1855; the lowest, 28.84 inches, 

 occurred near noon of February 19, 1854. Little change was ob- 

 served in the barometer during the fall of snow. 



The barometer fell during the blowing of all the winds except those 

 from about north by east and southeast. 



The observations indicate that the hottest winds are from the north- 

 east, one-half east, and the maximum atmospheric pressure nearly 

 east. 



This memoir was referred for critical examination to Professor 

 Peirce, of Cambridge, and Professor Chauvenet, of St. Louis. 



The next memoir is by Dr. John Le Conte, of Philadelphia, and is 

 intended to give a catalogue of the Coleoptera or beetles known to 

 inhabit the middle and eastern portions of the great central region of 

 temperate North America. The province here treated of includes 

 Kansas, a portion of Nebraska, and the eastern part of NeAv Mexico. 

 Its eastern limit is well defined, but its other boundaries are indefinite, 

 since it there fades imperceptibly into other provinces of the same great 

 zoological district. The descriptions of new species are principally 

 from specimens furnished through the Smithsonian Institution from 

 collections made by different explorers connected with the surveys of 

 the officers of the United States army. 



Before proceeding to describe the special materials used in the 

 preparation of the memoir, the author gives a short sketch of the 

 results already obtained in regard to the geographical distribution of 

 coleopterous insects in this country, illustrated by a map on which 

 the several regions are distinguished by different colors. From this 

 map it appears that the whole area of the United States is divided by 

 nearly meridianal lines into three or perhaps four zoological districts, 

 distinguished each by numerous peculiar genera and species, which, 

 with few exceptions, do not extend into the contiguous districts. 



