Harmer, S F, Ed.; Shipley, A E, Ed. <br/><br/>
Cambridge natural history, Vol.1: Protozoa, Porifera (Sponges), Coelenterata and Ctenophora, Echinodermata 

 -  Macmillan & Co. Ltd., New York  1906 
 - 671 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Zoology
<br/><br/><label>Dewey Class. No.: </label>591  HAR-C.1