ixm\ €Hft0tt and ^nnm^Uxt. 



BY J. G. GEENFELL, B.A., F.G.S. 



Head before the Geological Section of the British Association, 

 Bristol, 1875. 



I HA YE been fortunate in obtaining some fine specimens of 

 Encrinites from the base of tbe Carboniferous Limestone in the 

 gorge of the Avon. They occur in the two lowest beds of the 

 Black Ecck Quarry, just above the Lower Limestone Shales. Four 

 genera are found in the two beds — Poteriocrinus, Cyathocrinus, 

 Actinocrinus, Rhodocrinus — which latter genus does not include 

 PhiUips' Gillerisocrinus. By far the commonest species is Poterio- 

 crinus plicatus (Austin), of which I have obtained a fine series. 

 Hitherto only the body had been found — the arms, proboscis, and 

 stem being unknown. I will now describe this species, and in so 

 doing, and throughout the paper, I have adopted De Koninck's 

 nomenclature for the plates which form the body and arms. {See 

 plate VI. figs 1 to 4, and plate VIL, figs. 1 and 2.) 



I can find no traces of the three concealed plates above the 

 column mentioned by Phillips and Major Austin, and whose 

 existence was doubted by De Koninck. 



