Mr. Lyell on the Faluns of the Loire. 53 



doubtful, giving about seventeen per cent, of existing siDecies, a much 

 smaller proportion than was obtained by the author in other localities. 



Done. — At this town are extensive quarries of a calcareous build- 

 ing-stone, composed of comminuted shells and corals, and exposed 

 to the depth of forty feet. The beds are horizontal, but exhibit 

 highly inclined cross- stratification. From the marl-beds at La Gre- 

 zille, and the calcareous sand and limestone of Renaudan and Illet, 

 villages situated six or seven miles north of Done, Mr. Lyell pro- 

 cured twenty-four species of corals, four of Echinodermata and three 

 of fishes ; also a few species of shells, the most conspicuous being the 

 large Pecten soiarwm. In the great abundance of corals and Echi- 

 noderms, and the small number of Mollusks, Mr. Lyell states that 

 this deposit presents a perfect analogy to the white or coralline crag 

 of Suffolk ; but that its fauna is as distinct, with respect to species, 

 from the fauna of the coralline crag, as the other localities of the 

 Faluns of the Loire generally. 



Savigne. — Between Doue and Savigne the country consists partly 

 of the Eocene freshwater formation, which extends thence almost 

 continuously to Paris, and partly of Craie tnfeau. Near Savigne the 

 Falun is composed of limestone, containing most of the Doue fossils. 

 The result of Mr. Lyell's labours in this neighbourhood gave the 

 following amount of organic remains, obtained chiefly from a pit 

 which he had made near the point where the road from Savigne to 

 Channay divides from that leading to Courcelles. The total number 

 of species of cortds which have been determined amounts to eighteen, 

 of Echinodermata to two, of Testacea to seventy-six, and of fishes to 

 four. Mr. Lyell also obtained an upper molar of a deer, and a molar 

 of the Ckteropotamus Cnvieri. Of the shells, only ten species were 

 not found by the author at other Falun localities near the Loire ; and 

 twenty-three species, or about thirty per cent., have been identified 

 with recent shells. Among the fishes is Lamna contortidens , a spe- 

 cies which occurs in the Suffolk crag. The tooth ascertained by 

 Mr. Owen to belong to the C. Cuvieri, affords, Mr. Lyell states, an- 

 other instance of a mammifer common to Eocene and Miocene pe- 

 riods. 



District south of Tours. — The immediate neighbourhood of Tours 

 consists of cretaceous valleys, with intervening platforms of Eocene 

 freshwater strata. The Faluns occur from twelve to sixteen miles 

 to the south, at Louans, Manthilan and Bossee. At Louans the de- 

 posit is exposed in pits from four to five yards deep, and consists of 

 white and yellow marl, formed, to a great extent, of comminuted 

 shells and corals. From this bed Mr. Lyell obtained 180 species of 

 shells, many very small, and generally overlooked by collectors ; the 

 corals hitherto determined amount to only six species. Of the Tes- 

 tacea he procured all the species, except thirty-three, at other loca- 

 lities ; and the recent species have been ascertained to be about forty- 

 nine, or in the proportion of twenty-six per cent. At Bossee he 

 obtained 129 species of Testacea, forty of which, or thirty-two per 

 cent., have been identified with living shells ; and of the entire num- 

 ber Mr. Lyell found all except thirteen in some of the other Faluns. 



