Shrock, Robert R.  1875-1957. <br/><br/>
Principles of invertebrate paleontology / 
by Robert R. Shrock [and] William H. Twenhofel. 
 - 2nd ed. 
 - New Delhi ;  New York :  CBS Publishers & Distributors  c1953 [reprinted 1999]. 
 - xx, 816 p. :  illus. ;  24 cm. 
<br/><br/> Includes index.  "A revised and enlarged edition of Twenhofel and Shrock, Invertebrate paleontology." 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Invertebrates, Fossil.
<br/><br/><label>Dewey Class. No.: </label>562  / SHP 1999