PALiEONTOLOGIOAL REPORT OF GEOLOGICAL SURVEY. 477 



She of the specimen. Length of the pointed pieces, (the longest 



ece 5 ) -to\ inch. 



Length of the pointed pieces, (shortest piece,) - . T Vo m °b- 



Longest diameter across the points, - - I.-5 



Longest diameter of body, upper side, - - .-yW inch. 

 Longest diameter of body, lower side, - - . T Vo inc h- 



Height of body to junction of pointed pieces, - .-^ inch. 

 Height of body to highest point of pointed pieces, .^\ inch. 

 From mouth to nearest side, .... .^jl 

 From mouth to most distant side, - .^\ 



inches. 



inch, 

 nch. 



GENUS GRAPHIOCRINUS. De Koninck and LeHon. 



De Koninck and LeHon, who established this genus, have given 

 the generic formula as follows, viz : 

 *Basal pieces, 5. 



Radial pieces, 2X^. 



Anal pieces, 1. 



Interradial pieces, 0. 

 Arms, 10, not divided. 



GRAPHIOCRINUS— 14 BRACHIALIS. Lyon. 



(Plate I. fig. 1, 2 a, 26.) 



The anatomical structure of our species corresponds so nearly to this 

 genus that it is confidently referred to it. 



Column. A short piece of the column, still attached to our speci- 

 men, is composed of thin circular pieces, rounded on the margin, dif- 

 fering considerably in size — alternately a larger and smaller one ; 

 perforated ; the form of the perforation cannot be distinctly made out. 



Basal- pieces five; long lanceolate ; thick at the outer point; divided 

 by deep well defined sutures, from the inferior point of the primary 

 radials, to the opening of the columnar-pit, where the pieces join evenly 

 together; the superior points curved upwards, from the columns out- 

 ward; the pieces are grooved by a broad concave furrrow, which termi- 



*From the figure given by De Koninck and LeHon, I have much doubt if these are the true 

 basal pieces. Species of kindred form are found with fine basal pieces within the columnar de- 

 pression; these are generally covered by the column ; always alternating with the basal pie- 

 ces, as recognized in the above formula. There are another class of crinoids having a pen- 

 tagonal basal piece, not indented, divided by five sutures running from the columnar pit to the 

 centre of the shies, forming the pentagon. Zed&iniies Ma^lidfbrnU—Trodst, Is thus distil** 



