POTERIOCRINID-E PENTACRINUS. 119 



3. Species. Pentacrinus turerculatus. (Miller.) 

 Plate 15, Fignre 2 a, to 2 c. 



Description. — Tiie body of this criiioid answers to the generic definition as given in 

 a previous page. It differs from all other known species of Pentacrinus in the com- 

 parative massiveness of its column, and claspers. These lateral appendages occur in 

 series of five, with considerable intervals between each series. 



Synonymes and References. 



—Park. Org. Rem., vol.2, Plate \1, Jig. 2, and Plate 19,, fig. 2 

 — Whitehurst's Inq. into the Orig. state of the Earth, PI 7, 

 fig 1, and 2. 

 Pentacrinites tuberculatus. — Mill. Xat. Hist, of the Crinoidea, page 04. 

 . — Morris, Cat. Brit. Foss. page 56. 



Formation and Localities. 

 The Lias at Pyrton Passage, Gloucestershire. 



Miller, at page G4 of his work on the Crinoidea states that the P. tuberculatus is 

 found in a bed of rubbly lias, near the top of that group of rocks, which bed ranges 

 through a large portion of the inland counties — namely, Rutland, Leicestershire, 

 Northamptonshire, also through a portion of Gloucestershire. 



It will be seen on reference to figure 2 c, Plate 15, that the dorso-central plate of this 

 species is merely an enlarged and thickened columnar joint, without any indication of 

 divisions, a structure apparently common to all the Pentacrines, and which so clearly 

 distinguishes them from the more elaborately formed Extracrines. 



The rays of the P. tuberculatus are thick and bifurcated, but the total number of 

 dix-isions is unknown. If however the figure 2, PI. 1 9, vol. 2, Parkinson's Organic 

 Remains refers to this species, the final or temiinal rays are eighty. The figure here 

 alluded to appeared originally, we believe, in the 52d vol. of the Philosophical 

 Transactions. 



