Haeckel, Ernst,  1834-1919 <br/><br/>
Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Plates :  Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII  [electronic resource] / 
Ernst Haeckel 
 -  Project Gutenberg,  2013 
 - Project Gutenberg  44527 .
<br/><br/> Public domain in the USA. 
<br/><br/>Electronic text