109 



Asterias. A suborbicular, depressed body, divided at 

 its circumference into angles, lobes, or rays, disposed in a 

 stelliform figure. The lower surface of these lobes, or rays, 

 is furnished with a longitudinal groove, bordered on each 

 side with moveable spines, and with holes for the passage of 

 tubular and retractile feet. The mouth is beneath, and 

 central, and placed in the point where the grooves unite. 



The mouth, in these animals, opens directly into the 

 stomach, which has no other opening. It is, in fact, a 

 cul-de-sac^ augmented laterally by ten elongated and pin- 

 nated caecums, two in each ray, which proceed from the 

 sides of the stomach through three-fourths of the length 

 of the ray. 



These are the animals commonly known by the names 

 of star-fish, stellce marince, &c. 



Lamarck has had recourse to an arrangement of these 

 bodies, which is better adapted to facilitate their dis- 

 tinction and examination than any which has been hitherto 

 employed. He divides them into the scutellated and the 

 radiated asterice : under the former of which he places those 

 with continuous margins, such as pentetagonaster regularis, 

 pentaceros plicatus et concavus, &c. of Linck ; and, under 

 the latter, the numerous stelliform species. 



The fossil remains of the stelleridce are not frequently 

 found ; circumstances proceeding, in a great measure, from 

 the proneness to decomposition of the membranaceous 

 connecting matter. 



Fossil remains, referrible to the genera comatula, or 

 euryale, have been supposed to have been found by Rosinus 

 and by Lhwydd ; but there is sufficient reason for supposing, 

 that the remains which they described belonged to some 

 species of pentacrinites, of which we have yet to speak. 

 Two fossil specimens, apparently referrible to this genus, 

 are figured by Baier, in Supplementa Oryctographiae Noricae, 

 Tab. iii. fig. 3, 4. 



