PLATE 78. 



Fig. 1. • 340. 1. Glyptoceihus dbcadactylus. (Pag. 281.) 



1 a. A figure of a specimen, preserving a small portion of the column and the entire length of the fingers. 



1 b. Fragments of columns, composed of alternating large and smaller discs with angular edges. 



1 c. Section of the same. 



1 d. Section and figure of a similar fragment of a column enclosed in a coral. 



1 e. Fragment and section of a column where the discs are excavated on their upper side, and have plain 



rounded edges with a pentapetalous impression on the extremities. 

 I /. Fragment of similar character, having tlie upper edges of the plates fimbriated. 



1 g. Section of the same enlarged. 1 A. Magnified portion, showing tlie fimbriated edges of the discs. 



1 ». Separate plates or discs of a similar column, showing the variable character of the marginal crenulations, 



one specimen being marked by six prominent angles. 

 1 *. Two figures, showing the proportionate size of the larger and smaller discs in the columns, composed of 



plain alternating joints. 

 1 n. Fragment of a column, with the edges of the discs rounded and slightly nodulose : intermediate plates 



thin. 

 1 o. E^es of the discs rounded and nodulose ; intermediate ones thin, nodulose. 

 1 p. Edges of the discs rounded and smooth, the intermediate ones thin. 

 1 r. Edges of the discs flat and broad, the intermediate ones thin. 

 1 ». A fragment of slate with moniliform columns ; the intermediate plates often being scarcely distinct, while 



in others they are half as thick as the larger ones. 

 1 t. Large fragments of columns in the compact slaty rocks of the Hudson-river group, with the discs thick, 



the intermediate ones being scarcely visible. 

 1 u. A similar fragment of a column, with a section of the end, showing identity with the preceding figures. 



Fig. 2. 129. 1. Tentaculites flexuosa. (Pag. 284.) 



2 a. Fragment of stone with several specimens a, a, a, associated with corals, shells, etc. 



3 6. A specimen enlarged, showing the longitudinal striae. 



