J. T. Allan on the Forest-trees in Nebraska. 165 
nearly the amount of uncombined silex 
[To be continued. ] 
ART. XVII.—~Shetch of the Distribution of Forest-trees in Nebraska 
Territory ; by James T. ALLAN. (In a letter to Prof. Gray.) 
THE relative proportion of the several species and their gen- 
eral distribution in the tract of country lying west of the Missouri 
and between the paralells 40° and 438° is all that I will attempt 
to describe in this sketch. 
found only upon streams or small groves about some spring on 
the wide prairie. 
can in about equal quantities, with clumps of 
a@and Ulmus fulva in about eq q a ah eal ae thes 
