PEEBLE COUNTY. 409 



of the members found and reported in the counties to the eastward occur 

 here also, but, for the reason given above, they are not as easily marked. 

 The order of occurrence, it will be remembered, is the following : 



5. Cedarville or Guelph limestone. 



4. Springfield limestone. 



3. West Union limestone. 



2. Niagara shale. 



1. Dayton limestone. 



The three lowermost are somewhat obscure, and the third has not been 

 positively identified. The Eaton building-stone is not, as Dr. Locke sug- 

 gested, the equivalent of the Dayton stone, but belongs in No. 4 of the 

 above series, representing the building-stone of Springfield and Yellow 

 Springs. It constitutes the main resource of the northern portions of 

 the county. The same courses, together with the overlying Cedarville 

 or Guelph beds are also struck at New Paris. The upper beds are here 

 burned extensively into lime of the same approved quality which this 

 horizon everywhere furniishes in Central and Southern Ohio. The stone 

 agrees in its composition, and in all of its characteristics, with the Cedar- 

 ville beds, except that portions of it are highly fossiliferous. 



An analysis of the limestone of the Eaton quarries has been made for 

 the Survey by Prof. Wormley, and is here appended : 



Carbonate of lime ; 49.75 



Carbonate of magnesia '. 35.87 



Alumina andiron f. -'. 4.40 



SUicious matter 9.40 



99.42 

 The fossil contents of these divisions require no extended mention, 

 agreeing, as they do, very closely with the divisions of the same age 

 in the counties to the eastward. The well-known shell, Pentamerus 

 oblongm, is found in great abundance at Eaton, as is also the more 

 common of the Niagara trilobites, Calymene Blumenbachii, var. Niagarensis. 

 The latter fossil is more abundant here than at any other locality known 

 in the State, and occurs in great perfection. The limestone is magnesian 

 in character, and consequently all of the fossils are found as casts.*, 

 A trilobite, new to science, described by Prof Whitfield in the Paleon- 



* Mr. James Nelson, of Eaton, made the interesting discovery, several years since, of a 

 recent insect larva that bad occupied the mould of one of these trilobites from which 

 the fossil had been dissolved. The larva had adjusted itself in its growth to the space 

 left for it in the deserted mould so accurately as to suggest almost irresistibly, at first 

 sight, the idea that we had here the veritable remains of the soft parts of a trilobite. 

 The larva belonged to the order of insects termed neuropiera, and probably to the par- 

 ticular species corydalis cornutus, which is a common insect in Southern Ohio. 



