496 FOSSIL INVERTEBRATED ANIMALS. 



urchin, and who demonstrated that the Judaic stones were 

 nothing but the petrified points of these echini. But, notwith- 

 standing all that was said by this naturalist, the ancient errors 

 respecting the origin of echinites, subsisted until the time of 

 Aldrovandus, who demonstrated the true origin of these fossil 

 bodies. 



Luid was the last author who doubted that the fossil echi- 

 nides were true sea-urchins, because they were never found 

 provided with their points ; but the analogy of these fossil 

 bodies with those which are living, should have been quite suf- 

 ficient to prove this^ even though no examples had been seen, 

 as there have been, of fossil echini found with their points. 



The fossil echini, properly so called, are found in the strata 

 anterior to the chalk, and in those posterior to that substance ; 

 but it is more rare to find them in the chalk itself, in which, 

 however, some others of the same family are common ; and 

 those perhaps which have been found there depend upon the 

 cidarites as well as the echini, between which the line of 

 demarcation does not appear to be very clearly traced as to the 

 individuals in the fossil state. The localities of the fossil echini 

 are considerably various and extended. 



On the rest of the numerous genera of this family of zoo- 

 phites, as the cidarites, ananchites, &c., it is impossible to add 

 anything in a general way. We must, for the same reason, 

 pass entirely over the family of Stellerides, and conclude 

 with noticing whatever there may be of general interest in 

 the great order Polyparia. 



In employing the classic denomination of Polypi for the ani- 

 mals constituting the genera of madrepore, tubipore, eschare, 

 flustrum, &c., naturalists have necessarily been led to give 

 the name polyparium to the bodies more or less solid with 

 which these animals are found, without any respect to the 

 nature of these bodies, and still less to their form, and the 

 manner in which the polypi produce them, and are situated 

 in them. This word is synonimous with the words coral, coral- 



