CRINOIDEM. 



269 



like any flower of the fields, or to the mother stem Hke the branch of 

 a tree, until in due course they attained the almost adult state, when 

 the flexible stem which holds them fixed either to the soil or parent 

 stem breaks, and the animal, now free, launches itself into the liquid 

 medium, now resembling its parent form, and goes to live a proper 

 and independent existence ; in listening to a recital so opposed in 

 appearance to the ordinary laws of Nature, we should be inclined to 

 tax the narrator of such incredible facts with error or folly. Never- 

 theless, all these facts are now perfectly established. The being 

 which presents these marvels has nothing of the fabulous about it ; 

 it is the Cofuatida tnediterranea. 



In the Pentacrinoid stage of Comatula (Fig. 107), the presence of 

 a digestive apparatus has been distinctly traced. It is a sort of 

 irregular sac, with a central mouth on the upper surface, and another 

 orifice situated at a little distance from the mouth, and evidently 

 intended as an outlet for the products of digestion. The arms of 

 these creatures, which are spreading or folded up, according to their 

 wants, are provided with ambulacra! feet, which, serving at once as 

 organs of absorption and ha\ing vibratile cilia, are at the same time 

 organs of respiration. Such are these curious beings : they occupy a 

 sort of middle or transition state between animals permanently fixed 

 to some spot and those capable of motion, representing in our own 

 times the last remains of extinct generations. Every specimen of 

 the Crinoidese furnished with arms presents evidence of their repro- 

 duction or re-integration. 



ASTERIAD^E OR StaR-FISHES. 



In walking on the sea-shore at low tide, your eyes have often seen 

 the animal which commonly and sometimes scientifically bears the 

 name of star-fish half-buried in the sand. It is so regular and geo- 

 metrical in its form that it has more the appearance of being the 

 production of man's hand than of being a creature which breathes and 

 moves. The divine Geometrician who created it never realised a 

 creature more regularly finished in shape or more perfectly harmo- 

 nious in symmetry, 



OpHIURIDjE. 



The Ophiuridae are thus named from two Greek words (o^u, a 

 serpent, and ovpa, a tail), from their fancied resemblance to the' tail 

 of a serpent. These Echinoderms are met with in almost every 

 sea, both in those of the tropical and temperate regions ; they are 



