110 



Fossil remains of the genus ophiura are very rarely to 

 be met with. A specimen is figured by Bourguet, Traite 

 des Petrifications, Planche lix. 438, in which a considerable 

 portion of the central part of the animal of one of the spe- 

 cies is preserved. A very perfect specimen of this genus, 

 imbedded in chalk, was purchased by Mr. Donovan at the 

 sale of the Leveriaii Museum. 



Fragments of the genus asterius are found more fre- 

 quently than of the preceding genera ; and, of the scutel- 

 lated sort, more frequently than of the radiated. A fossil 

 specimen of the former, approaching to pentagonaster semi- 

 lunatus of Linck, is figured by Schultz, Bertrachtung der 

 Versteinerten, Tab. ii. fig. 6, from Pirna. A similar spe- 

 cimen is figured. Organic Remains, PL i. fig. 1 ; and at 

 PI. i. fig. 3, is represented a chalk fossil resembling penta- 

 gonaster regularis, Linck ; asterias regularise Lamarck. 

 Mr. Knorr gives the figure of an impression in flint of an 

 asterite of this kind. 



A fossil, in a yellowish coloured limestone, in the writer's 

 cabinet, bears a tolerably close resemblance to astropecten 

 echinatns minor, Linck, Tab. viii. No. 12. Some fragments 

 of an asterite apparently similar are figured in the supple- 

 ment to Knorr's work, PI. vii. Book iii ; and a petrification, 

 somewhat similar, from Malesme, in France, is figured by 

 Guettard, Mem. del' Acad. An. 1763. Similar fossils are 

 also found in the blue clay of Sheppey Island. Fossils of 

 minute animals approaching to some of the preceding ge- 

 nera, deserving careful examination, appear to exist in St. 

 Peter's mountain, and in the neighbourhood of Verona. 



The facts which have been pointed out in a preceding 

 work, respecting the structure of such of the encrinital and 

 pentacrinital remains as were then known, evinced that the 

 animals to which they belonged ought not to be placed, as 

 has been done by our justly celebrated teacher, Lamarck, 

 among the polgpi natatites, but rather among the echinoder- 



