6 t platycrinid^. — c vathocrinus. 



Synomymes and References. 

 Cviithocrinus bursa.— Pliill. Geol. York. 2. t. 3./. 29. 



Formation and Localities. 

 Moiuitain limestone — Yorkshire. 



The C. bursa is small, and like the last species, was of rare occurrence in the 

 carboniferous ocean ; but we may yet hope to obtain more instructive specimens than 

 that fiom which our figure is taken, which shews nothing of the rays or column. 



6. Species. Cyathocrinus conicus. (Phillips.) 

 PI. VIII. fij. 1, a, b. 



Definition. — The dorso-central plate is quinque-partite; first series of perisomic plates 

 five; second series six, five of which bear the rays. 



Synonymes and References. 

 Cyathocrinus conicus. — Phill. Geol. York. t. III. ftg. 27. 

 Formation and Localities. 



Mountain limestone — Bolland ; Ireland. 



The Dorso-central Plate, and all the perisomics of the C. conicus, are narrower, 

 less raised m their centres, and longer than in any of the other known Cyathocrini; 

 these peculiarities give it much the air of a Poteriocrinus for which it may easily be 

 mistaken unless attention is paid to the number and arrangement of the plates. 



All the plates appear to be finely granulose. 



7. Species. Cyathocrinus mammillaris. (Phillips.) 

 , PI. 1. fig. 8, a, b. 



Definition.— Dorso-central plate quinque partite; first series of perisomic plates five, 

 all tumid in their centres; second series six, five of which bear the rays. 



