1881.] NATURAL SCIENCES OF PHILADELPHIA. H*? 



REVISION OF THE PALJSOCRINOIDEA. 

 BY CHARLES WACHSMUTH AND FRANK SPRINGER. 



Part II. 

 Family SPH^ROIDOCRINID^, 



INCLUDING THE SUB-FAMILIES 



PLATYCRINID^, RHODOCRINID^, and ACTINO- 

 CRINID^. 



The first part of this work was published contemporaneously 

 with the " 3d Lieferimg " of Professor Zittel's " Handbuch der 

 Palaeontologie," which embraces the Crinoidea. 



In his classification, this distinguished author follows Johannes 

 Miiller, and divides the Crinoidea into three orders : Eucrinoidea 

 {Brachiata^W\\\\Q\-)^ Gyst'oidea, and Blastoidea ; subdiA'iding the 

 first into the Tesselata, Articulata, and Costata. The " Tesselata " 

 agree in general features with our PalseocrinoideajeLnd the Articu- 

 lata with the mesozoic and recent Crinoids, for which we have 

 proposed the name Stomatocrinoidea ; but while we treat these 

 groups as of the same rank with the Blastoidea and Cystoidea, 

 they are, according to Miiller and Zittel, mere subdivisions of the 

 '' Brachiata:'^ 



Zittel divides the Tesselata into twentj'-six families, among 



1 While this was in press, we received from Dr. Etheridge, Jr., and 

 P. Herb. Carpenter, an intei-esting paper upon the genus AUagccrmus, a 

 new form from the Carboniferous of Scotland, which they consider to be 

 "tesselate" in the younger, "articulate" in the adult state. In a dis- 

 cussion upon Miiller's terms, Tesselata and Artieulata, they arrive at the 

 conclusion, that at the present state of our knowledge of these Crinoids 

 those names are inappropriate and should be abandoned. They adopt our 

 name Palceocrinoidea, but object to Stomatocrinoidea, as they think it 

 possible, that also Crinoids of the other group might have possessed an 

 external mouth. They consider the irregular an-angement of the plates in 

 the calyx, against the almost perfect symmetry which is found throughout 

 the other group, and the vault structure, to be better and more persistent 

 characters for distinction than the condition of the mouth. We can only 

 notice here this important paper, but shall take pleasure to refer to it at 

 some future time. 

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