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Show 100 MR. G. NEVILL ON THE [Feb. 17, tiana, but also in close proximity to most of the deposits A to E; but though fragments were very numerous all round, I could never succeed in finding a single bit even undoubtedly associated with these subfossils, which I here attribute to the " phases eozoique et dizoi'que." 2. INTERMEDIATE PERIOD. Under this heading I comprise a certain number of species, characterized by tbe remarkable gigantic Helix pavetiana, Issel, which can be found, here and there, all along this part of the Riviera, and which most certainly, in m y opinion, are of a more recent age than the preceding; most of them are closely allied forms to those still found living in this submaritime zone. This zone of H. paretiana requires still further investigation, a matter of considerable difficulty, as the mollusks do not appear as yet to have been found actually in situ. Those I found were evidently isolated washed-down specimens, mostly in bad condition, and incrusted in the rock, from which it was often impossible to extract them. At Cape Mortela, indeed, where they occur at a considerable depth (perhaps some 40 or 50 feet below the surface), they are preserved in better condition in the comparatively soft " Couche Marneuse." Immediately above them here, in perfectly similar deposit, occurring at a depth of, approximately, 10 feet or so, can be found in profusion present-existing species, such as H. aspersa, H. vermiculata, H. cespitum, Pupa multidentata, Rumina decollata, Cyclostoma elegans, &c. The most characteristic forms I found immediately associated with H. paretiana were Hyalina olivetorum and H. herculcea, a variety of Rumina decollata much stouter and larger than the existing form, one or two species of the group Xerophila, allied to, but quite distinct from, X. cespitum, which is found in profusion immediately above, and two species of the group Tachea, &c. I think this " Couche Marneuse " at Cape Martela clearly proves H. paretiana and its associated mollusks to have immediately preceded the present fauna, without any very marked break, either of change in the climate or otherwise. 3. PRESENT PERIOD. This I should divide into two well-marked zones, having but very few species in common, Pupa quinquedentata being a marked exception- Submaritime and Subalpine Zones. A. Submaritime Zone.-Especially characterized by species of Xerophila, Macularia vermiculata, Leucochroa candidissima, Rumina decollata, Ferussacia and Ccecilianella spp., Clausilia solida, It is, perhaps, worthy of notice that I found the common species of Pomatia, Xerophila, &c, almost without exception, of larger dimensions than those recorded as "major" in Pfeiffer's Monogr. B. Subalpine Zone.-On account of m y bad health I was unable to explore the higher elevations, where many interesting forms doubtless still remain to be discovered. My friend Coombe Williams was good enough to make several expeditions to the summits of the neigh- |