Hemicidaris crenularis Lamarck
Matrix free complete test. Lovely preservation and detail. from a 'classic; old locality. A 'beauty'.
Upper Jurassic, Lower Oxfordian, Argovian.
Carriere de Mont St. Martin, Mesmont, Ardennes, France.
Echinoid : 2.9 x 2.9 x 1.9 cm.