88 



PETRIFACTIONS AND THEIR TEACHINGS. CHAP. II. 



but occasionally with only four angles ; in some species the 

 sides are acute, in others rounded : the articulating surfaces 

 are for the most part richly chased with floreal or radiated 

 striae, and grooved. 1 The arms in some species are very long 

 and greatly subdivided, becoming extremely attenuated, 

 and the ossicula proportionably minute. The exquisite beauty 

 of the plumose encrinites when expanded on slabs of limestone 

 and petrified by pyrites, is exemplified in several examples in 

 the Case under review. 2 



LiGN.23. PENTACRINITES HIEMERI; PART OF A GROUP ON LIAS LIMESTONE, FROM 



BOHL, WlRTEMBURG.* 



(J- Nat. size.) 



PENTACRINITES HIEMERI. Wall-Case G. On the large slab 

 of Lias limestone affixed to the wall in the centre of this Case, 

 is an exquisite group of thirty Pentacrinites, exposed in relief 

 on the surface of the stone, in as perfect a state as if just 



1 " Pictorial Atlas," PI. XLVII. The Briarean Pentacrinite is fully 

 illustrated and described in detail in Dr. Buckland's Bridgewater 

 Essay, p. 484. 



2 "Pictorial Atlas," PI. LI. LIT. 



3 This species was named and figured by M. Konig in his " Icones 

 Fossilium sectiles" PI. III., fig. 29, in 1826* 



