Data PolicyPublications | Persons | Institutes | Projects IMIS Photogallery » References Coelopleurus (spines + ambulacral tubercles) Description Left: C. maculatus: The cross-section of the primary spines is triangular. Right: C. undulatus: The ambulacral primary tubercles decrease in size towards the apical system.Left: Scale 0.5 mm; Right Scale 5 mm. Author Mortensen, Theodor JPG file - 112.33 kB - 945 x 488 pixels added on 2011-02-23536 viewsFrom reference Schultz, H. (2011). Sea urchins III: Worldwide regular de... © 2011 Mortensen, Theodor Click here to return to the thumbnails overview