Hegner, Robert William,  1880-1942. <br/><br/>
Invertebrate zoology / 
Robert W. Hegner, Joseph G. Engemann. 
 - 2nd ed. 
 - New York :  Macmillan,  1968. 
 - xviii, 619 p. :  ill. ;  24 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Invertebrates.