232 / TRANSACTIONS OF THE 



DESCRIPTION OF A NEW SPECIES OF FOSSIL ASTERIAS 

 (ASTERIAS ANTIQUA). By G. Troost, M.D. 



This description is extracted from a partial report on 

 the geology of the state of Tennessee, which was read in 

 the house of representatives, at the session of 1832. 



Naturalists speak in a doubtful manner, whether the 

 Asterias is found in a fossil state. Alexander Brongni- 

 art, in his valuable geognostical description of the en- 

 virons of Paris, mentions two places in which some frag- 

 ments of Asterias were found ; the one in the upper 

 chalk (see page 15, 2d edition, Des articulations qui 

 par leur forme ciihoide paraissent avoir appartenu a une 

 espece voisine de V Asterias aurantiaca). The second 

 seems to have been found in strata having some analogy 

 with the Calcaire grossiere of Paris, and was sent to 

 Brongniart from the vicinity of Ghent (see page 196, 

 Portions ou Articulations Asterias), I suppose it 

 is on the authority of Brongniart, that Defranc enumer- 

 ates amongst the Stellerides, one Asterias in the fossil 

 state, and as being doubtful whether it occurs posterior 

 to the chalk. [Defranc, Tableau des Corps Organises 

 Fossiles, page 102.) 



Our fossil belongs to the division with a radiated body, 

 as established by Lamarck, and is composed of five rays, 

 having a longitudinal groove, which in our species is nar- 

 row. These rays, five in number, are in proportion 

 shorter than those in the A. spinosa, which it resembles, 

 as to its external form. Our specimen measures from 

 extremity to extremity of two opposed rays, two and 

 two-fifths inches ; the rays from the disk to its extre- 

 mity measure one inch. The A. spinosa, which has 



