7. Body soft and transparent, with a pair of jaws working within the body; 



usually but not always with one or more rings of cilia on the front 

 end; sometimes colonial 



Rotifers (Chapter 4) 

 Body worm-like; without visible internal jaws; with or without bristles 

 along the sides of the body 



Worm-hT^e or Leech'li\e Animals, Annelids (Chapter 5) 



8. With a ring of tentacles 



Moss'li\e or ]elly'li\e Animals (Chapter 3) 

 No tentacles, but often with bristles or cilia 9. 



9. With tufts of bristles or cilia or with one or more rings of cilia in the 



area of the mouth; sometimes colonial 



Rotifers and Gastrotricha (Chapter 4) 

 Not so 



Worm-IiT^e and Leech'li\e Animals (other than Annelids) 

 (Chapters) 



KEY TO THE NON-MICROSCOPIC LAND AND 



FRESH- WATER ANIMALS 



L With legs 2. 



No legs; sometimes with setae or tufts of bristles along the sides 8. 



2. With fur, hair or feathers 3. 

 No fur, hair or feathers 4. 



3. With hair or fur; with two pairs of legs, or sometimes with the fore 



limbs modified to form wings 

 Mammals (Chapter 15) 

 With feathers; with one pair of legs and one pair of wings 

 Birds (Chapter 14) 



4. Animals without a backbone; usually with more than two pairs of legs; 



almost always with antennae or with external biting or sucking mouth 

 appendages; often with wings 

 Arthropods (Chapter 7) 

 With a backbone; with one or two pairs of legs; no external biting or 

 sucking mouth appendages; skin usually slimy or with scales 5. 



5. With the skin slimy, unsealed; no external ear openings 6. 

 With a scaled skin or with external ear openings 7. 



6. Body usually slender and with a tail; young are usually with gills 



Salamanders (Chapter 9) 

 Body fat, without a tail in the adult, except in the male of one species; 

 the young or tadpoles have tails, very fat bodies, and no or one or two 

 pairs of legs each 



Frogs and Toads (Chapter 10) 



7. With a leathery or horny shell 



Turtles (Chapter 13) 

 No shell 



Lizards (Chapter 11) 



23 



