222 ESSAY ON CLASSIFICATION 



secondary consideration, upon which he establishes four types among 

 the Artiozoaria: 1st. The Osteozoaria, corresponding to Cuvier's 

 Vertebrata; 2d. The Entomozoaria, corresponding to Cuvier's Articu- 

 lata; 3d. The Malentozoaria, which are a very artificial group, sug- 

 gested 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, corre- 

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

 zoaria, contains organized beings which for the most part do not be- 

 long to the animal kingdom. Such at least are his Spongiaria and 

 Dendrolitharia, whilst his Monodaria answer to the old class of In- 

 fusoria, about which enough has already been said above. It is evi- 

 dent 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 improvements. Among Vertebrata, for instance, he has for 

 the first time distinguished the class of Amphibia from the true Rep- 

 tiles. He was also the first to remove the Intestinal Worms from 

 among the Radiata to the Articulata; but the establishment of a 

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

 ception. Notwithstanding some structural peculiarities, the Chitons 

 are built essentially upon the same plan as the Mollusks of the class 

 Gasteropoda, and the investigations made not long after the publica- 

 tion 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 partake more of the character of orders than of 

 that of classes, whilst among Mollusks his class Cephalophora cer- 

 tainly includes two classes, as he has himself acknowledged in his 

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

 Zoophytaria partake again of the character of orders and not of those 

 of classes. One great objection to the system of de Blainville is the 

 useless introduction of so many new names for groups which had al- 

 ready been correctly limited and well named by his predecessors. He 

 had, no doubt, a desirable object in view in doing this — he wished 



