The Cambridge Natural History. Volume 1 
 Protozoa, Coelenterates, Echinoderms, etc. 

<br/><br/> Protozoa  Hartog, Marcus  Porifera (Sponges)  Sollas, Igerna B.J.  Coelenterata & Ctenophora  Hickson, S.J.  Echinodermata  MacBride, E.W.