h. — side view of tlie abdominal bulb shewing the excavation for the insertion of the ray 

 joints. The pointed and smaller abdominal plates, ^vith the meso-plate, are seen 

 to advantage in this specimen. 



c. — dorso-central aspect, Avith the mark of columnar attachment. 



(I. — upper portion of the column of P. raucronatus ] 



e. — pointed abdominal plate. 



f. — meso-plate, interscapular of Miller. 



Fig. 2. Platycrinites elongatus, //, /«, /. 



</. — lateral aspect. 



h. — lateral aspect shewing the proboscis. 



i. — enlarged view of a specimen with six perisomic plates. 



Pig. 3. Platycrinites anthelioxtes, k to v. 



k. — lateral view of the abdominal bulb exhibiting the basal joints of the rays. 



I. — apex showing the abdominal plates, with tlie four maxillary plates surrounding the 



valvate mouth in the centre. 

 m. — lateral aspect exhibiting the utmost degree of elongation to wliicli tlie mouth could 



be protruded. The beautifid arrangement of the abdominal plates round the 



polygonal meso-plate is in this figm'e distinctly seen. 

 n. — loAver joints of the greater and lesser rays. 



0. — dorso-central plate ■^^dth central radii for the attachment of the column. 

 j>. — dorso-central aspect. 



q. — perisomic plate shewing the excavation for the articiUation of the ray joint. 

 r. — ^polygonal meso-plate. 



The specimens from which the figures in PI. I. are taken, with the exception of fig. 

 m, were collected by the authors fiom the carboniferous limestone of Ireland. Fig. m 

 is di'aAvn from the identical fossil which Miller took for the t}'pe of the genus, and which 

 is rej)resented as magniticd thrice in his Nat. Hist, of the Crinoidea. PL 1. page 74. 

 Miller added a portion of column from an unattached fragment. 



The figures in PI. II., with the exception of g, h, are draAvn fi'om specimens in the 

 fine collection of the Bristol Literary and Philosophical Institution, the Curator of 

 which, Mr. Stutchbury, has Idndly fiu'thered our researches. Fig. 2. A, was obtained at 

 Woodspring, near Clevedon, Somersetshire, by Mr. AVm. Morgan, to whose kincbiess 

 we are indebted for the opportunity of taking the illustration. 



The P. mucronatus appears to be identical with the fossil which Mr. Phillips has 

 figured as the P. kevis in the Geology of Yorkshire. 



