12 



CHAPTER II. 



LINN^AN ARRANGEMENT OF SHELLS. ANIMALS WHICH 



INHABIT THEM. 



X HE Animal Kingdom is divided by Linnseus into six classes : 



The 1st, MAMMALiI, , are viviparous. -V These have a heart with 



> 2 auricles and 2 ventri- 



The 2d, A VES, are oviparous. J cles, warm red blood. 



The 3d, AMPHIBIA, with lungs. -\ These have a heart with 



> 1 auricle and 1 ventri- 



The 4th, PISCES, with external gills. J cle, cold red blood. 

 The 5th, INSECT A, with antennee. "1 ^J"^'^ ■^r'^ ^'•^^'■' 'fl" 



' ' I 1 auricle and no ventri- 



The 6th, VEmiES, with tentacula. J ^{^.^^ " '"^^ ^^"'^^ "'^ 



The sixth class, VERMES, or Worms, contains five orders: 

 The 1st order is Intestina, or Worms, usually so called. The 

 greatest number of these inhabit the bodies of other ani- 

 mals. 

 The 2d, Mollusc a, are of a soft substance, not covered with a 

 shell, and generally furnished with tentacula or feelers 

 (which are wanting in the order Intestina). These are 

 mostly inhabitants of the sea ; their forms are exceed- 

 ingly various, and many of them very extraordinary. 

 The 3d, Testacea, are MoUusca covered with a shell. These 

 are very numerous ; some inhabit the sea ; others fresii 

 water ; and others again tlie land. 



