Professor Quenstedt, in his Handbuch der Petrefaktenkundo (1852), first described and figured, under the name Cotylederma, a remarkable fossil, which he found adherent to the surface of Ammonites striatus in the upper region of the Lias c. It formed a flat, sessile, cylindrical little bowl, composed of five plates, with five blunt angles, and was referred by him to the class Echinodermata and the order Crinoidea. The learned author, in his “der Jura” (1858), says that he has found it attached to Ammonites lineatus and A. striatus in the upper region of Lias γ, at Aselfingen, and that it was comparable to the calyx of a crinoid.