. Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments. Geology. Bulimus lubricus. Loess, and Achatina ; which two last are nearly allied and pass into each other. The Ampullaria (fig. 50) is another genus of shells, inhabiting rivers and ponds in hot countries. Many fossil species have been referred to this genus, but they have been found chiefly in marine formations, and are suspected by some eonchologists to belong to JVatica and other ma- rine genera. All univalve shells of land and freshwater species, with the excepti
. Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments. Geology. Bulimus lubricus. Loess, and Achatina ; which two last are nearly allied and pass into each other. The Ampullaria (fig. 50) is another genus of shells, inhabiting rivers and ponds in hot countries. Many fossil species have been referred to this genus, but they have been found chiefly in marine formations, and are suspected by some eonchologists to belong to JVatica and other ma- rine genera. All univalve shells of land and freshwater species, with the exception of Melanopsis (fig. 41), and Acha- tina, which § has a slight indentation, have entire mouths; and this circumstance may often serve as a convenient rule for distinguishing freshwater from marine strata; since, if any univalves occur of which the mouths are not entire, we may presume that the formation is marine. The aperture is said to be entire in such shells as the Ampullaria and the land shells (figs. 45— 49), when its outline is not interrupted by an indentation or notch. Ampullaria glauca, from the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Lyell, Charles, Sir, 1797-1875. New York, D. Appleton and co.
Size: 1873px × 1335px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, booksubjectgeology, bookyear1868
