514 FOSSIL INVERTEBRATED ANIMALS. 



support certain pieces which are not found — or organs, not cal- 

 careous, and which could not be preserved. 



It appears that the layers, or slices, which composed these 

 bodies, may have been detached one from the other after the 

 destruction of the polypus ; for they are sometimes found iso- 

 lated. Many figures of these kinds of fossil polyparia may be 

 seen in the works of Parkinson and Knorr. 



The Caryophylliy being divided into five parts at their head, 

 and being changed into calcareous spath, appear to have many 

 relations with the encrinites. 



The generic name of Pentacrinus was given by M. Oken 

 to a species of living encrinus, inhabiting the sea of the An- 

 tilles, and which he thus characterises : — Stem articulated ; 

 very long, pentagonal, bearing verticillated branches in different 

 points of its length, and a similar one at the summit. The 

 name of Pentacrinite had been anciently given by Knorr and 

 other writers to the species of encrinites whose stem has five 

 faces. In the Natural History of the Crinoidea, by Mr. Miller, 

 this name has been given to a genus, in which that gentleman 

 recognizes the following characters : — An animal, with a co- 

 lumn formed of numerous junctures, with five sides or faces ; 

 articulated in their surface by marks, with five semi-striated 

 petals. The upper juncture of the column, supporting a pelvis 

 with five junctures, on which are five supports of the first ribs, 

 followed by five of the second ribs, and by five of the shoulders, 

 from which proceed ten arms, having each two hands, com- 

 posed of many tentaculated toes. 



It is not easy to suppose that any specimens could have 

 contained, with exactitude, all the characters here detailed. 

 The figures, however, of the species referred to this genus by 

 Mr. Miller, are to be found in Parkinson's Organic Remains. 

 These species are four in number, viz. — P. caput MeduscB, P. 

 briar eus, P. subangulariSf P. basaltiformis, and belong to the 

 lias of this country. 



It is important to observe that, though this genus, until the 



