This genus of shells belongs to the Class Gasteropoda of Cuvier, and to the family Turbinacea of Lamarck, of which the general character is to have the shell turreted or conoid, with the aperture rounded or oblong, and the margin disunited.

M. Michelotti was induced to undertake the examination of the fossil Italian species of this genus, from the doubts prevailing regarding the identity of some of the species in the writings of authors. He describes in all ten species, which are found in the neighbourhood of Turin, of which four have not been previously noticed. The four newly described species are Solarium neglectum, S. pulchellum, S. Lyellii, and S. humile. Two of the other species described, viz. S. Stramineum, Lamarck and S. luteum, have their living prototypes,—the first in the Indian and Mediterranean Seas, and the second in the seas of New Holland.