Subject
2 free books about echinodermata, free to read online. Chapter 1 of any book is free, no account needed.
A guide to the shell and starfish galleries: (Mollusca, Polyzoa, Brachiopoda, Tunicata, Echinoderma, and Worms)
British Museum (Natural History). Department of Zoology; Bell, F. J. (Francis Jeffrey); Kirkpatrick, R. (Randolph); Smith, E. A.
Het Leven der Dieren: Deel 3.8, De Stekelhuidigen, Plantdieren en Sponsen
Alfred Edmund Brehm
