PERIOD OF CUVIER.

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ing some structural peculiarities, the Chitons are builtessentially upon the same plan' as the Mollusks of theclass Gasteropoda , and the investigations made not longafter the publication of De Blainville ’s system have leftno doubt that Cirripedia are genuine Crustacea. Thesupposed transition between the Articulata and Mollusks ,which De Blainville attempted to establish with his typeof Malentozoaria, certainly does not exist in nature.

If we apply to the classes of De Blainville the testintroduced in the preceding chapter, it will be obviousthat his Decapoda , Heteropoda, and Tetradecapoda par-take more of the character of orders than of that ofclasses, whilst among Mollusks , his class Cephalophoracertainly includes two classes, as he has himself acknow-ledged in his later works. Among Badiata his classesZoantharia, Polypiaria, and Zoophytaria partake again ofthe character of orders and not of that of classes. Onegreat objection to the system of De Blainville is the use-less introduction of so many new names for groups whichhad already been correctly limited and well named by hispredecessors. He had, no doubt, a desirable object inview in doing this,—he wished to remove some incorrectnames ; but he extended his reform too far when heundertook to change those also which did not suit hissystem.

CLASSIFICATION OF EHRENBERG.

The characteristics of the following twenty-eight classes of animals, witha twenty-ninth for Man alone, are given more fully in the Transactions ofthe Academy of Berlin for 1836, in the paper q. a., p. 208.

1st Cycle: Nations. Mankind, constituting one distinct class, is charac-terized by the equable development of all systems of organs,in contradistinction of the

2nd Cycle: Animals, which are considered as characterized by the promi-nence of single systems. These are divided into :