Chap. III. PERIOD OF CUVIER. 199 



series ; only that tie Blainville inverts the order of Lamarck, beginning with the 

 highest animals and ending with the lowest. With that idea is blended, to some 

 extent, the view of Cuvier, that animals are framed upon diflerent plans of structure ; 

 but so imperfectly has this view taken hold of de Blainville, that instead of 

 recognizing at the outset these great plans, he allows the external form to be 

 the leading idea upon which his primary divisions are founded, and thus he divides 

 the animal kingdom into three sub-kingdoms : the first, including his Artiozoaria, 

 with a bilateral form ; the second, his Actinozoaria, with a radiated form, and the 

 thinl, his Heterozoaria, with an irregular form (the Sponges, Infusoria, and Corallines.) 

 The plan of structure is only introduced as a secondary consideration, upon Avhich he 

 establishes four types among the Artiozoaria : 1st. The Osteozoaria, corresponding to 

 CuAaer's Vertebrata; 2d. The Entomozoaria, corresponding to Cuvier's Articulata; 

 3d. The Malentozoaria, which are a very artificial group, suggested only by the 

 necessity of establishing a transition between the Articulata and Mollusca ; 4th. 

 The Malacozoaria, corresponding to Cuvier's Mollusca. The second sub-kingdom, 

 Actinozoaria, corresponds to Cuvier's Radiata, while the third sub-kingdom, Hetero- 

 zoaria, contains organized beings which for the most part do not belong to the 

 animal kingdom. Such at least are his Spongiaria and Dendrolitharia, whilst his 

 Mouodaria answer to the old class of Infusoria, about which enough has already 

 been said above. It is evident, that what is correct in this general arrangement 

 is borrowed from Cuvier; but it is only justice to de Blainville to say, that in the 

 limitation and arrangement of the classes, he has introduced some valuable improve- 

 ments. Among Vertebrata, for instance, he has, for the first time, distinguished 

 the class of Amphibia from the true Reptiles. He was also the first to remove 

 the Intestinal Worms from among the Radiata to the Articulata; l)ut the establish- 

 ment of a distinct type for the Cirripedia and Chitons was a very mistaken con- 

 ception. Notwithstanding some structural peculiarities, the Chitons are built essen- 

 tially upon the same plan as the Mollusks of the class Gasteropoda, and the 

 investigations, made not long after the publication of de Blainville's system, have left 

 no doubt that Cirripedia are genuine Crustacea. The supposed transition between 

 Articulata and Mollusks, which de Blainville attempted to establish with his type of 

 Malentozoaria, certainly does not exist in nature. 



If we apply to the classes of de Blainville the test introduced in the preceding 

 chapter, it will be obvious that his Decapoda, Heteropoda, and Tetradecapoda par- 

 take more of the character of orders than of that of classes, whilst among Mol- 

 lusks, his class Cephalophora certainly includes two classes, as he has himself acknowl- 

 edged in his later works. Among Radiata his classes Zoantharia, Polypiaria. and 

 Zoophytaria ])artake again of the character of orders and not of those of classes. 

 One greit objection to the system of de Blainville is, the useless introduction of so 



