298 ROCHESTER ACADEMY OF SCIENCE, [June 25, 



The method of formation of this and similar deposits is within 

 the province of the geologist to describe ; a work which Mr. G. K. 

 Gilbert has already done in a most satisfactory manner. 



On the lake side the accumulation seems to be pure sand and 

 gravel, upon which the flora is very limited, but there is a considera- 

 ble number of large trees. Indeed, this beach has more of the arbo- 

 real vegetation than we are accustomed to see upon such sandy 

 beaches. 



Toward the marshy border, where a rich black alluvial deposit 

 has mingled with the sand, the ordinary flora of such districts flour- 

 ishes. At the immediate margin where Long Pond in its fluctuations 

 sometimes encroaches, more or less of a marshy tract is left, and 

 becomes the favorite habitat of rushes, sedges and aquatic grasses ; 

 also other plants of which I will speak hereafter. And finally in the 

 shallow water are the true water-plants found in similar situations in 

 other localities. 



The changes which have taken place since man became an inhab- 

 itant of the beach are to be noted, since some members of our flora 

 are shy of the footsteps of man, and do not gracefully accept civiliza- 

 tion. Some plants which I recognized when the beach was in a com- 

 paratively primitive condition, I have not seen for some time. 



Of the Raiiunciilacece, the peculiar water form of Ranunculus aqua- 

 tiiis, var. trichophyllus, finds here the requisite conditions for growth 

 and flourishes correspondingly. Ranunculus Pennsylvanicus is not 

 infrequently found on the borderland of moisture. The water lilies 

 are so abundant in the water they need scarcely be mentioned. Cakile 

 A?nericana is increasingly abundant. So far as I have noticed 

 this so-called sea-rocket favors sandy lake beaches in preference 

 to maritime borders. Elodes Virginiana was found so near to 

 Long Pond that it cannot practically be excluded from our list. 

 Hibiscus Moscheutos, the elegant swamp rose-mallow, was noticed 

 a few years since by Rev. John E. Baker, in the marsh on 

 the opposite side of Long Pond and adjacent to Cranberry Pond ; 

 it was also observed in 1892 by others. Lathy rus maritimus was for- 

 merly found in more or less abundance near to the sandy shores of the 

 lake. I think it has passed away in the conflict for existence. 

 Astragalus Canadensis, which is the only species of this genus 

 having a foothold here, but which is abundantly represented in 

 some portions of the West beyond the Mississippi, is increasingly 

 abundant, indicating that by the aid of its rather shrubby growth it 



