NEW AGELACRINITES 187 



showis only the under surface, it is not yet possible to state that 

 they were not sculptured exteriorly like A. h a m i 1 1 o n e n si s. 

 Jaekel thus has wisely regarded Haplocystites synonynnous with 

 Agelacrinites. Future knowledge of this fossil may indicate that 

 Haplocystites is the proper designation for the bodies which have 

 been termed Echinodiscus or Lepidodiscus. 



Agelacystis is a name proposed by Haeckel as a substitute for 

 Agelacrinites because the latter is not a crinoid. It has no 

 gitanding whatever. 



Great minds have ever thought in unison. And so it came 

 about that in the year 1897 it was discovered by the 

 acute American paleontologist, Mr. Miller,^ and by the dis- 

 tinguished E'nglish geologist and explorer^ Dr J. W. Gregory,^ 

 that the term Echinodiscus had long ago been employed as 

 a generic name among the Echinoderma, and hence its dupli- 

 cation was inadmissible. Mr Miller exercised his preeminent 

 right to correct his error by proposing to replace the unintended 

 synonym with the word, Ageladiscus.^ This was in October of 

 that year, but already in February Dr Gregory had introduced 

 the term, Discocystis, with the same intent. 



Thus three different generic names have been introduced for 

 three very dubious specimens of agelacrinites, of which two 

 doubtless belong to the same species and of all three of which 

 very little has been known. No wonder that the eminent Eng- 

 lish echinodermist, Dr Bather, in a late work should indicate a 

 sluggish receptivity for these names.* 



This is the nomenclatorial history to the present of these 

 peculiar bodies. Our new material from the Chemung sand- 

 stones enables us to carry it forward, and it is hoped at the 

 same time to elucidate these polynomial structures. 



The Chemung agelacrinite (A. a 1 1 e g a n i u s), like all its later 

 allies, was sessile but not fixed. No specimen has been seen 



^ North American geology and paleontology. 2d appendix, p. 744. 



2 Quar. jour. geol. soc. 1897. 53: 123-36. 



3 North American geology and paleontology. 2d appendix, p. 734. 

 * Lankester's Treatise on zoology. 1900. pt 3, p. 303. 



