99 



from its form, it being thought to resemble the nave of a 

 wheel, to which five spokes were attached. This fossil was 

 first noticed by that industrious naturalist, Martin Lister, 

 who describes it as being about the size of a wallnut, but 

 hollow, and rounded into five double points, in the figure of 

 crescents, and having on its bottom the impression of a 

 trochites, or a trochites itself yet adhering: the surface he 

 describes as being formed of rough polygonal plates.* 

 Several specimens of these fossils are represented. Organic 

 Remains, vol. ii. PI. xvii. since which Mr. Cumberland has 

 favoured us with the figures of several others of very curious 

 structure, in a very interesting communication, in the fifth 

 volume of the Geological Transactions. 



. Among the benefits resulting from the researches of the 

 fossilist, is that of being sometimes able by the contained 

 fossils, to trace beds of marl and clay to the rocks from the 

 decomposition of which they have proceeded. Thus several 

 of the specimens discovered by Lister were described as 

 having been found in the soft earth in the villages of 

 Braughton and Stock in Craven, whilst their subsequent dis- 

 covery in the mountain-lime of Mendip, and in that neigh- 

 bourhood, manifests the original bed into which they had 

 passed. Thus, the pear encrimte may be found rather to 

 belong to the magnesian limestone rocks than to the white 

 clay, as it is termed, which may have proceeded from the 

 decomposition of these rocks : agreeable to this opinion. 

 Dr. Capeller, in a letter to Scheuchzer, describes and figures 

 some of these fossils, with the fingers attached, from the 

 magnesian limestone of the island of Gothland. 



Sp. 5. The plumose encrinite. — This fossil is distinguished 

 by its long fingers, partly naked and partly furnished with 

 articulated tentacula, disposed like the feathery appendages 



on the sides of a quill This fossil was described in Organic 



* Philosophical Transactions, vol. x. 



