62 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 54. 



Reference to the maps (figs. 1 and 2) will show that the two moun- 

 tain stations he within the Tolland region and that Denver on the 

 plams is also so located as to be of direct use when compared with the 

 other two stations. In discussmg chmate, special attention has been 

 given to precipitation and temperature, because these two factors of 

 chmate seem to be those most directly of interest in relation to the 

 fauna under study. 



Precipitation. — The usual increase of precipitation with elevation is 

 well marked in this region and seems to continue to the highest ele- 

 vations, as is shown in Table 1. 



Table 1. — Annual precipitation. 



The plains are decidedly an arid region. Denver is fairly typical 

 of the entire eastern plains of the State, but there are places where 



Fig. 3.— Mean precipitation by months. 



the rainfall is only 11 or 12 inches. The arid climate of the plains 

 seems, as will be pointed out later, to play the chief part in determin- 

 ing the nature of their entomostracan fauna. The greater precipi- 

 tation of the mountain region is probably of little importance directly, 

 but has its chief significance in the fact that a large proportion of it 

 comes in the form of snow. Reference to figure 3 shows that at 

 Corona the greater part of the precipitation comes in those months 

 when it is entirely in the form of snow (all months but June, July, 

 and August). At the higher lakes, great banks of snow accumulate 



