and other plants. The shape and venation of leaves is 

 well preserved, one of the most common kinds being 

 that of Hjrpericum kalmianum which grows over much 

 of the surface. On this prairie as well as on the Oxford 

 prairie grow many plants not found east of the Huron 

 river either in Erie county or the counties beyond. 



Sandusky and Margaretta as well as Marblehead 

 Peninsula and Kelley's Island are underlaid by Corni- 

 ferous limestone which comes near the surface over 

 much of this region. In many places, especially on 

 Marblehead, the covering of soil is only a few inches or 

 a fraction of an inch deep and consists of partially 

 decomposed vegetation and lime carbonate derived 

 from the underlying rock. Quite a number of species 

 are characteristic of this calcareous soil. Catawba 

 Island, as it is called, and the islands of the Put-in-Bay 

 group have a similar character but the rock is older, 

 belonging to the Waterlime formation. Over the great- 

 er part of Sandusky and in many places on the islands, 

 the limestone is covered with clay of variable thickness, 

 but in many parts the soil is too thin for trees to attain 

 a large size, for even if they could obtain nourishment 

 enough, they are likely to be uprooted by a strong 

 wind. The glacier that passed over this region left 

 traces that still show in hundreds of places, including 

 some grooves on Kelley's Island and Marblehead 

 which so far as we know are unsurpassed elsewhere in 

 the world. It is interesting to observe that the grooves 

 on the different Islands, on the Peninsula and in 

 Sandusky and Margaretta have the same direction, 

 running about twelve degrees south of west, or parallel 

 with the axis of Lake Erie, excepting a few which have 

 quite a different direction and indicate a movement of 

 the ice at a different time. Where the superimposed 

 drift has protected the rock from weathering, it not 

 only retains the deep grooves but shows everywhere a 

 highly polished surface marked with fine parallel lines. 



