10 ZOOLOGY. 



Okdek 1. Hydrostatica. pi. I^^fig. 5, Di/pMes. 



" 2. AcALEPHiA. Medusa. PI. I^ifig- 6, Velella. 



Class 4. EcMnodermata. 



Radiated animals with a hard integument, like those on 2)1-76, figs. GO 

 to Tl. Some have and some are without locomotive organs. 

 Okdek 1. Epedicellata. PL 7 4:, Jig. Y, Sijnmculus. 



" 2. Pedicellata. pi. 74:, Jig. 8, Holothuria, Asterias, Echinus, &c. 



Class 5. Intestina. 



In this class (excluding the Annelida) Cuvier placed the intestinal worms, 

 and others which bear some resemblance to them, but which are not 

 confined to the internal parts of animals. 



Order 1. Entozoa [Gamtaria, Cuvier). Pi. 74c, Jig. 9, Ligula. 



" 2. Sterelmintha {Parenchymata, Cuvier). Fig. 10, Nemertes. 



Division II. Mollusca. 

 Class 1. Acephala. 



This class has no proper head, the mouth opening immediately into the 

 anterior part of the body. The gills are suspended upon each side of the 

 body. The Tunicata are without an external shell ; the Conchifera have a 

 bivalve shell. 



Order 1. Tunicata. PI. 74:, Jig. 11, Botryllus. PI. 77, Jig. 3, Salpa. 

 " 2. Conchifera. PI. 74:, Jig. 12, Ostrea. See also_^?. 76, Jigs. 25-50. 



Class 2. Gastropoda. 



In this class locomotion is effected by means of a fleshy disk, called a 

 foot, upon the lower surface of the body. The orders are distributed 

 according to the structure of the branchite. This class is abundant in 

 species, and includes the greater part of the univalve shells. 



Order 1. Cyclobranchiata. PI. 74:, Jig. 13, Chiton. 



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