Orr, Robert T.,  1908- <br/><br/>
Vertebrate biology / 
by Robert T. Orr 
 - 3rd ed. 
 - Philadelphia :  Saunders,  1971 
 - vii, 544 p. :  ill., maps ;  25 cm. 
<br/><br/>Includes bibliographical references and index 
<br/><br/><label>ISBN: </label>0721670172 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Vertebrates
<br/><br/><label>Dewey Class. No.: </label>596