New American Paleozoic Ostracoda. 



179 



NEW AMERICAN PALEOZOIC OSTRACODA. 

 By E. O. Ulrich. 

 No. 1. Ctenobolbina and Kirkbya. 



Since the publication of my paper on " New and Little 

 Known American Paleozoic Ostracoda," in Volume XIII of 

 the Journal of the Cincinnati Society of Natural History 

 (1890-91), much new material has been collected and picked 

 over, in part or wholly. The earlier washings, of which 

 samples merely had been searched in 1890, have now been 

 almost entirely worked out. The result is an astounding 

 number of new species, the number of the undescribed forms 

 falling little short of two hundred ! 



Perhaps the most interesting of all the localities furnishing 

 ostracoda is the Bryozoa bed, at the Falls of the Ohio, oppo- 

 site the city of Louisville, Ky. In 1890, when my former 

 paper describing species from this locality w 7 as written, 

 the pickings from the small sample of washings then 

 examined was believed to give a fair, if not a full, idea 

 of the species occurring there. How far from the truth 

 this conception was, and how other localities when carefully 

 investigated may be expected to add, more or less largely, to 

 the number of known species, is shown by the fact that, when 

 the last of the washings from the Falls in my possession had 

 been searched the number of species known from that 

 locality was nearly doubled. 



This continual accession to the number of known forms 

 proves that we have not yet reached that point where an 

 approximately stable classification of the paleozoic represen- 

 tatives of the class is possible. My aim, therefore, in this and 

 succeeding papers, in which I hope to publish illustrations 

 and brief descriptions of the new species and varieties, is 

 principally to add to the facts and data pertaining to specific 

 variation, and to leave the restriction and characterization of 

 the genera and families to such a future time when the dis- 

 covery of more or less disturbing new forms will have become 

 comparatively rare. 



Jour. Cin. Soc. Nat. Hist., Vol. XIX, No. 6.) j 



Printed June 26, 1900. 



