126 
Having had at my disposal only internal, but very perfect, casts of 
this species, I can say nothing positive about the ornamentation with which 
the external surface may have been furnished ; hut in carefully examining 
each sub- radial impression, one can easily see five folds, faintly indicated, 
springing from a common central well-defined point, and directed perpen- 
dicularly towards the middle of each of the five sides. This arrangement 
presents a great analogy to the fossil figured and described by Dana under the 
name FentacUa corona (PL IV, fig. 10a) . Indeed, this fossil corresponds so 
well in form and size with the suh-radials of our Cyatliocrinus, that I am led to 
believe it may he nothing more than one of these plates. In that case these 
suh-radials would he ornamented, not only with the radiating costse that I 
have just mentioned, hut also with concentric granulated strise parallel to 
the margins, of which Dana’s Pigs. lOi and 10c give a very good idea. 
The calyx, the middle of which is much inflated, narrows at its summit, 
so that the circumference intended to receive the insertion of the arms 
has only half the diameter of the largest diameter of the calyx taken at about 
the middle of its elevation. The column must have been relatively very thin, 
judging from the small size of the surface intended for the insertion of the 
topmost joint. 
Dimensions} — The total length of the calyx is fifty-five millimetres ; 
the diameter, eighty millimetres ; the average length of the suh-radials, forty 
mil lim etres ; the transverse diameter of the same, forty-seven millimetres ; 
the length of the radials, twenty-seven millimetres ; the transverse diameter 
of the same, forty-two millimetres ; the diameter of the base, forty-four milli- 
metres ; and the length and breadth of the first anal piece, sixteen millimetres. 
Affinities and Distinguishing Characteristics. — I know of no other 
species of Cyathocrinus which reaches such a large size as this, and which could 
he confounded with it. It is at the express desire of Mr. W. B. Clarke that 
I have retained the name under which he sent it to me. 
Horizon and Localities. — The internal casts, figured by me, were found 
in a rather friable greyish sandstone, at Osterley,^ on the Hunter. Fentadia 
corona comes from the Illawarra. 
^ The two specimens obtained being slightly imperfect, the measurements given must be considered as 
only approximate. 
^ [Osterley is a house on the left bank of the Hunter River, between Morpeth and Raymond Terrace, the 
formation being Upper Marine, and close to the horizon of the Muree Beds. — T.W.E.T).] 
