180 ON SYSTEMATIC ZOOLOGY. 



(230.) III. The third great division of M. Cuvier is 

 composed of the articulated animals, of which Insects 

 present the typical perfection. The whole group is 

 divided into four great sections: — 1, The Annelides, 

 or red-blooded worms ; 2. The Crustacea, or crabs ; 

 3. The Arachnides, or spiders ; and, 4. The Insecta, or 

 insects. It is in this part of his laborious work that 

 our author has found it necessary to call in the assist- 

 ance of M. Latreille, from whose pen the whole of the 

 third and fourth volume has proceeded. We advert to 

 this fact, as the circumstance has been overlooked by 

 some modern writers, who have attributed to one what 

 belongs to the other. 



(231.) IV. The fourth and last division of our author 

 comprises what he terms the radiated animals, or 

 Zoophytes (^Animalia radiata) ; although the term 

 belongs but to a small part of those he has placed 

 under this denomination. The group, in fact, com- 

 prises two classes of animals, so totally different, that 

 we cannot but feel surprise they should have been asso- 

 ciated together. One of these groups constitute the 

 Acrita, or polypes ; the other the true Radiata of this 

 work. In other respects the arrangement before us is 

 highly valuable, and evinces that intimate acquaintance 

 with the details of these animals which laid the found- 

 ation for the brilliant career of this incomparable anato- 

 mist. Under these circumstances we feel compelled 

 to be more particular on this class than the last. 



(232.) The class of Zoophytes is divided by M. 

 Cuvier into five large groups, viz. : — 1 . The Echino- 

 derma, or the star-fish and sea eggs, forming the genera 

 Astcrias and Echinus of Linnaeus. 2. The Intestina, 

 intestinal worms. 3. The Acalephce, or medusas. 

 4. The Polypi, or polypes. And, 5. The Infusoria, or 

 animalcules. Each of these, again_, are divided in the 

 following manner : — 



