OP CONCHOLOGY. 127 



II. Suctorial. Live either on vegetable or animal juices. Haus- 

 tellata, Rhachiglossata, Toxoglossata, and, according to 

 Swainson, most birds. Agassiz considers the suctorial in- 

 sects superior to the mandibular. (Am. Journ. of Science, 

 1850, p. 383.) 

 Cataphages swallow the food entire, as most fishes, Acephala 

 Actiniae. 



The teeth are chiefly destined to divide the food in morsels, 

 but are often only prehensile organs. The want of teeth is 

 counterbalanced by the muscular structure of the intestinal 

 channel (Birds), by hard plates in the stomach (Bulla, Gryllo- 

 talpa), or by swallowing purposely gravel for triturating the 

 food (Myrmecophaga, Sthruthio), or unusually strongly de- 

 veloped salivary glands and liver. The want of teeth is only of 

 generic value, — e. g., Myrmecophaga, Baloena, Cirroteuthis, 

 Doridopsis, Thetys, Odostomia. The teeth are probably always 

 present in quite young animals (e. g., Balasna, Odobana), and 

 are lost in the adult state. ' No example to the contrary is as 

 yet known. 



XII. According to the elements in which animals live, they 

 are either Terrestrial (Arial) or Aquatic. 



Lungs and gills afford no limits for the higher systematic di- 

 visions, but only relative rank. 



1. Perterrestrial (Dana) live in all stages of their life upon 

 land, and are nearly exclusively pulmonary (Cyclostoma). 



a. Arboreal or scansoreal, with prehensile organs, — hands, 

 tail, or suckers, (Quadrumana, Bradypus, Chamaeleo, Hyla, 

 Limax). 



^. Rasorial, Ungulata, Gallinacea. 



7". Cursores. 



d. Saltatores (Halmathurus Rana, Locusta Strombus, Onus- 

 tus). 



e. Herpetometra (Geometra, Pedipes, Stoastoma). 

 ^. Repentes, Serpentes, Gastraeopoda. 



^. Fodientia, Talpa, Gryllotalpa. 



C. Voliantia (Birds, Bats, most Insects). 



Divisions composed of flying animals are always analogous to 

 divisions containing swimming animals. Locomotion in air and 

 water is performed in an analogous manner (Birds, Fishes, Bats, 

 Seals). 



2. Semiterrestrial animals undergo their first metamorphosis 

 in the water, or are much dependent upon water; Rana, 

 Auricula. 



Amphibious animals are, according to their respiratory organs, 



