According to Petit and Harasewych (1990, Catalogue of the Superfamily
Cancellarioidea Forbes and Hanley, 1851 (Gastropoda: Prosobranchia). The
Nautilus, Supplement 1: 69 pp.), Cancellaria gradata was described by M.
Hörnes (1854, 319, pl35, figs. 2a-b) from the Miocene of Austria. Reference
to the original description is: Hörnes, M. 1851-56. Die fossilen Mollusken
des Tertiär-Beckens von Wien. I. Univalven. Abhandlungen der
Kaiserlich-Königlichen Geologischen Reichsanstalt 3: [pages and plates
published in sequence between years 1851-56; pages 297-384 and plates 33-40
were published in 1854]. Petit and Harasewych observed that: "Moriz Hörnes
and Rudolph Hoernes, although father and son, used different orthography
for their surname." Hope this helps, and that you can find Hörnes's work
somewhere in Italy.

Saluti,

Jose
__________________________________________________________________________
Jose H. Leal, Ph.D.
Director, The Bailey-Matthews Shell Museum
Editor-in-chief, THE NAUTILUS
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