314 ON THE CLASSES OF THE 



paring them, after the example of Linnaeus, to an EchinuS' 

 It becomes thus necessary for us, after having repelled the 

 idea of any affinity existing between Coronula and the 

 Mollusca, to consider the former animal as it relates to 

 the Radiata, with which Latreille has allowed the Cirri- 

 pedes to be evidently connected. 



None of the Mollusca present a vestige of being truly 

 articulated ; for the imbrication of the shells of a Chiton, or 

 of the processes of other shells, does not surely deserve this 

 epithet in the sense in which it is applied to the skeleton of 

 the AnnuloseorVertebrated animals. Insects and Crustacea 

 therefore, the basis of whose structure is articulation, can- 

 not without great violence be connected with the Mollusca. 

 The Vertebrated animals have a truly articulated axis ; 

 and, as we have ascertained them to be connected 

 with the Annulosa, we have now consequently to investi- 

 gate, what animals of a type of form distinct from either 

 an Annulose or a Vertebrated animal present a vestige of 

 articulation. Every zoologist will at once answer that 

 such are the Echinoderma of Cuvier. It did not escape 

 the notice of this anatomist, that the Radiata ought imme- 

 diately to follow the Jnnulosa, so that in this respect 

 there is nothing new in the above observations. The only 

 question that has remained undecided is simply this. 

 Which of the Annulosa come the nearest to the Radiata^ 

 If the order in the Regne Animal be the real one, the ge- 

 nus Nycterihia comes the nearest to Echinus and Asterias; 

 but as no reasons are assigned for this arrangement, and 

 as it is not very evident, I shall be allowed to differ from 

 the order there laid down. Nay, I trust even to be 

 excused for hazarding the publication of my opinion, that 

 the Crustacea of all the true Annulosa come the nearest 



