1 86 The Ohio Naturalist. [Vol. VII, No. 8, 



often argillaceous composition as well as the red muds, resulting 

 from extensive weathering, suggest similar conditions of deposi- 

 tion. The approximate correlation of these .deposits is then as 

 follows : 



INDIANA. OHIO. 



Sellersburg beds Delaware limestone 



Jeffersonville limestone 



Geneva limestone ^ Columbus limestone 



Northward in both states the line of division between these 

 formations becomes less distinct and in the northern part of the 

 southern Indiana area Dr. Kindle remarks that "associated with 

 the loss of individuality of these two formations occurs a ming- 

 ling of their two faunas which renders them indistinguishable as 

 separate faunas."'' To a very limited extent the same is true 

 in Ohio where we find species belonging to the Columbus lime- 

 stone of central Ohio well up in the Delaware of the northern 

 part, but the preponderance of Hamilton species in the upper 

 formation is even greater in northern than in central Ohio. 



The full meaning of these similarities is rather hard to state 

 definitely but they certainly indicate contemporaneous deposi- 

 tion and more or less open communication during their forma- 

 tion, and that the sea bordering the eastern shore of the Cincin- 

 nati land area was not essentially different from that which 

 washed the western shore of the same. 



SUCCULENT PLANTS OF OHIO. 



Nellie Ely. 



The typical succulents are characteristic of desert and saline 

 regions. There are, however, some fleshy and watery plants 

 which grow in shadv and moist places, which show some of the 

 peculiarities of typical succulents. The structures of the xero- 

 phytic succulents are highly specialized to harmonize with the 

 usual conditions of the desert. Thickening of the epidermis, 

 the comparatively small number of stomata, the more or less 

 globular form of the stem or leaves in certain species, and the 

 development of special water-storage tissues are among the most 

 striking adaptations to be found in the plant kingdom. 



Succulents may be divided into two groups according to their 

 specialized parts. Leaf succulents, in order to restrict transpi- 

 ration, reduce the surface of their leaves which become more or 

 less cylindrical or globular in shape. These leaves have in their 

 tissuse peculiar cells, called water-storage cells which serve for 



4. Ibid. p. 570. 



