2IO The Ohio Naturalist. [Vol. XI, No. 1, 



Hibiscus zone is coming in. Twenty feet east of the western 

 margin of the belt the marsh zones are interrupted by a boat-house 

 on the beach with a runway for boats extending into deeper 

 water. The development of the marsh formations on the north 

 side has thus been interfered with; and the margin is also more 

 exposed to storm winds and waves. A sandy beach GO feet wide 

 is building; it is occupied in part by the Polygonum-Scirpus and 

 in part by the Scirpus lacustris zone. 



At the south end of the section studied both lateral zonation 

 and layering (etagen) are strikingly shown. There is a marked 

 increase in elevation from one lateral zone to another, from the 

 floating Nelumbo leaves to the tall Ulmus americana and Quercus 

 palustris. This is well shown in the photographs. There is a 

 poor development of etagen in the individual associations. In 

 some there are the dominant plants and then the ground cover, in 

 others a weak irregular growth of taller herbs, while in the forest 

 the shn.ibs have either been cut or arc young plants, and the vines 

 generally trail over the ground. 



I wish to take this opportunity of expressing my appreciation 

 of and thanks for the favors shown me by Dr. Alfred Dachnowski, 

 under whose supervision the survey was made, to Mr. Lionel King 

 for the two excellent photographs and to Mr. Booton and Mr. 

 Sawyer of the State Canal Commission for the map and informa- 

 tion concerning the acreage and history of Orchard Island. 



AN OPEN VALLEY NEAR HARRISBURG, OHIO.* 



" R. H. Nichols, 



The subject under investigation is an open valley near Harris- 

 burg, Ohio, on the B. & O. Railroad about fifteen miles southwest 

 from Columbus. This valley at one end joins Big Darby valley 

 near Harrisburg; at the other end after a circuitous course of 

 about three miles on the west side of the creek it again joins 

 Big Darbv. 



About a mile from the north end the water parts at present on 

 a divide (see map) consisting of two small alluvial fans. The 

 topographic map shows a small stream entering the valley at the 

 divide from the west and flowing northward through the valley, 

 but today this stream is buried in a tile drain and no stream nor 

 channel can be fotmd in this part except a very short one at the 

 end of the valley. 



* This paper covers a field problem worked out as a part of the course in 

 Advanced Physiograph}^ given by Dr. George D. Hubbard at Ohio State 

 University. 



