Data PolicyPublications | Persons | Institutes | Projects IMIS Photogallery » References Chaetodiadema africanum (apical system + ambulacral plates) Description a. Apical system (the periproctal membrane is shaded). b. Ambulacral plates on the oral side: The primary tubercles are traceable down to the peristome (lower edge).Scale 4 mm. Author Mortensen, Theodor JPG file - 138.90 kB - 945 x 677 pixels added on 2011-02-23277 viewsFrom reference Schultz, H. (2011). Sea urchins III: Worldwide regular de... © 2011 Mortensen, Theodor Click here to return to the thumbnails overview