PRELIMINARY NOTES ON CINCINNATIAN AND LEX- 

 INGTON FOSSILS OF OHIO, INDIANA, 

 KENTUCKY, AND TENNESSEE. 



Aug. F. Foerste. 



By far the best fossils for the accurate discrimination of the 

 various Cincinnatian and Lexington horizons of the area of the 

 Cincinnati geantichne are the bryozoans. Possibly, in the future, 

 the ostracods may be of great service. If the brachiopoda. and 

 some of the other more common groups of fossils are to be added 

 to this list, a much more extended subdivision of forms, based upon 

 slighter differences, will be necessary. It is not likely that such 

 subdivisions of recognized species will commend themselves to 

 those who are engaged in the broader problems of paleontology, 

 but these subdivisions are necessary if all the available material is to 

 be employed in the discrimination of the different faunas at the 

 different horizons. Whether these subdivisions are to appear in 

 literature as species or as varieties is another question. A great 

 convenience of the Linnean binomial system is its restriction of 

 names to two terms. This convenience is lost if too many terms 

 appear under the trinomial form of varieties. 



The Cincinnatian formations are rich in forms which are in the 

 process of evolution, resulting in numerous groups within which 

 the varieties are closely connected by abundant intermediate forms. 

 In this wealth of material some investigators will see species where 

 others see only varieties, or scarcely even the latter. In this case it 

 will be well to remember that the object of the investigation will 

 often determine the attitude of the investigator. The present paper 

 is for the purpose of supplying material for the discrimination of 

 Cincinnatian horizons. 



Incidentally, it has been attempted to determine more accur- 

 ately the type forms and horizons of some of the species already 

 described. The best excuse for this preliminary publication of 

 material is that it has already brought fruit in the renewal of inves- 

 tigations in the field from which former students, owing to other 

 and more important interests, had departed. 



