Whittington, H.B.  <br/><br/>
Silicified middle ordovician trilobites  

 - New York  The Geological Society of America   1954 
 - [5], 137p.   Illustration  24cm x 16cm  
 - The Geological Society of America : Memoir 59 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Trilobites<br/>Paleontology - Ordovician <br/>Ordovician geologic period <br/>Paleontology
<br/><br/><label>Dewey Class. No.: </label>565.393  / WHI