226 PROCEEDINGS OF THE ACADEMY OP [1879. 



revision of the pal.2e0crin0idea. 

 by charles wachsmuth and frank springer. 



Introduction. 



According to Miller's catalogue of American paleozoic fossils, 

 there have been described, in this country alone, up to the summer 

 of 1877, about 800 species of Crinoids, not including Blastoids and 

 Cystideans. If we add to this number some 400 species from Europe 

 an estimate which is certainly not exaggerated when we remem- 

 ber that Schultze described from the Devonian of the Eifel alone 

 73 species ; DeKoninck and Le Hon from Belgium 45 ; and An- 

 gelin from the Silurian of Sweden 176 we have from both coun- 

 tries about 1250 species. Making due allowance for synonyms, 

 we have possibly 1000 good species, which are distributed among 

 from 150 to 175 genera. Many of the latter were established at 

 a time when our knowledge of the Crinoids was in its infancy. 

 They were frequently founded upon one or two species, often, in- 

 deed, on a single imperfect specimen ; which resulted in many de- 

 fective, insufficient, and not unfrequently incorrect descriptions, 

 producing endless perplexing complications afterwards 



There was a time when nearly every fossil Crinoid was IJncri- 

 nites. This was the case almost until 1821, when J. S. Miller de- 

 scribed his well-known genera Poteriocrinus, Actinocrinus, Pla- 

 tycrinus, Rhodocrinus, and Cyathoc?*inm, which have been uni- 

 versally adopted by the later paleontologists with the exception, 

 perhaps, of Cyathocrinus, which was badly defined by him. As 

 new species were discovered, the founding of additional genera 

 progressed, and generic distinctions came to be recognized be- 

 tween groups of forms, which substantially agreed in the arrange- 

 ment of the plates of the body, but differed in the anal plates, 

 the construction of the arms, and other characters to which but 

 little attention had before been paid. Through such separations 

 it resulted in many cases that the parental genus was divided up 

 into a number of genera, and it finalty became evident that some 

 of the features which had been considered of mere generic im- 

 portance, were family characters. The majority of the genera 

 thus established have been adopted by most of our leading pale- 



