LOWER HELDERBERG ROCKS. 12« 



COLUMNS OF UNDETERMINED CRINOIDE^. 



PLATE in A. 



Fig. 3 & 5. Fragments of columns of different species of crinoids, probably of Mariacrinus. 



Fig. 13. A root and base of Ae column of a species of Mariacrinus ? probably M. pachy- 

 dactylus. 



Fig. 14. Fragment of a column with long node-like joints ; its relations unknown. 



PLATE VI. 

 Fig. 7, 8, 9 & 10. Fragments of pentagonal columns, bearing nodes at the angles, which 

 seem to have been the bases of little branchlets. 



Fig. 11, 12 & 13. Sections of pentagonal columns, showing varying degrees of angularity, 

 till in the last one the angles project in wing-like appendages. 



Fig. 14. Fragment of Lower Pentamerus limestone, with pieces of columns of two or more 

 species. 



Fig. 15. Section of a pentagonal column, showing marks of longitudinal division at the 

 angles. 



CYSTIDEiE OF THE LOWER HELDERBERG GROUP. 



Genus LepOCRIXLS*, or LePADOCRIMJS (Conrad). 



In his Annual Report for 1840, Mr. Conrad introduced the following 

 notice of a new crinoid : 



'^ Lepocrinites gcbhardii. By this name I introduce a singular fossil found 

 " by Mr. Gebhard. The body is composed of plates of unequal sizes, a 

 " few of which have ambulacra, connecting this fossil with the Echino- 

 " dermata : lower half of the column apparently solid, and traversed 

 " by a pentagonal canal." 



Figures of the bases of the column of this fossil were given in the Final Report 

 of Mr. Vanxjxem on the Third Geological District of New- York, 1842 j and the 

 same, with a figure of the entire fossil, was given by Mr. Mather in liis Report on 

 the Geology of the First District, 1843, page 346, under the name previously 

 proposed by Mr. Conrad. 



• The name Lepoerinitet was given from the resemblance to the Lepas or Barnacle, ^nati/a, and is 

 properly Lepadocrinut. It will be noticed that these observations upon the relations of this fossil were 

 published five years before the paper of Vov Bccb on Cystidese. 



