312 The Ohio Naturalist. [Vol. VIII, No. 6, 



siderable Lenina trisulca. Around the borders of the pond is a 

 vigorous growth of the following species from the adjoining forest 

 formation : 



Impatiens biflora, 



Dryopteris spinulosa , 



Dryopteris thelypteris , 



Geranium robertianum, 



A dice a pumila, 



Washingtonia claytoni. 



Back of the cottages near the Government Dock there is a 

 swampy area which evidently represents advanced stages of the 

 lagoon succession in a lagoon which must have been initiated dur- 

 ing severe northwest storms in the Bay. The depression is long 

 and narrow and runs almost at right angles to the general direc- 

 tion of the large sand ridges of the Ridge Section, and is very 

 nearly parallel to the general direction of the shoreline of the 

 Bay near by. The vegetational structure of this depression is 

 approximately a Calamagrostis Wet Meadow Formation in the 

 central portion and rapidly invading this area from the sides is 

 the Cephalanthus-Cornus Thicket Formation, around which, 

 and in many places in which, is a strongly developed Rhus hirta 

 Thicket Formation. 



THE-BEACH-SAND PLAIN-THICKET-FOREST SUCCESSION. 



In the time intervals between the initiation of the great sand 

 ridges on Cedar Point there was, evidently, a gradual accumu- 

 lation of sand along the beach of the Ridge Section of the penin- 

 sula, causing an outward growth of the land form without the 

 building up of ridges, or, if ridges were initiated by the cutting 

 off of lagoons, the sand drifted in from the adjoining land and 

 from the new beach to such an extent that the lagoons were 

 soon filled, the final result being, in either case, a level expanse 

 of sand plain elevated but a few feet above the level of Lake Erie. 



A considerable portion of Cedar Point consists of what may 

 be called Sand Plain. This habitat comprises: (a), the k^-el 

 expanses between the ridges of the Ridge Section; (b), the main 

 part of the Bar Section; and (c), a large proportion of the Dune 

 Section, including also the more or less transitional portion of the 

 peninsula between the Dune Section and the Ridge Section 

 where part of the amusement tents and trinket stands of the 

 Pleasure Resort are located. It is very difficult at times to draw 

 more than an arbitrary line between sand plain and dune, es- 

 pecially in the Dune Section ; both these physiographic structures 

 owe their elevation above Lake level to the accumulation of wind 

 drifted sand and differences of topography rather than of origin 

 must be taken into consideration when an attempt is made at 

 classification. 



