. Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments. Geology. Spirifer trigonalds, Martin, sp. Mountain Limestone. Derbyshire, &c. Spirifer glaber, Martin, sp. Mountain Limestone. more numerously represented in these carboniferous rocks than in the secondary formations described in former chapters; individually, as Professor Ramsay has observed,* they may outnumber the lamellibran- chiate mollusks, although the species of carboniferous lamellibranchiate more than double the contemporary brachiopoda. The increasing num ber o
. Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments. Geology. Spirifer trigonalds, Martin, sp. Mountain Limestone. Derbyshire, &c. Spirifer glaber, Martin, sp. Mountain Limestone. more numerously represented in these carboniferous rocks than in the secondary formations described in former chapters; individually, as Professor Ramsay has observed,* they may outnumber the lamellibran- chiate mollusks, although the species of carboniferous lamellibranchiate more than double the contemporary brachiopoda. The increasing num ber of the last-mentioned group among the bivalve mollusca, both in genera, species, and individuals, will be found to be a marked feature in the fauna of the primary rocks the lower we descend in the series. Among the brachiopoda or palliobranchiate mollusks, Terebratula hastata deserves mention, not only for its wide range, but because it often retains the pattern of the original colored stripes which orna- mented the living shell. (See fig. 573.) These colored bands are also preserved in several lamellibranchiate bivalves, as in Aviculopecten (fig. 574), in which dark stripes alternate with a light ground. In some also of the spiral univalves, the pattern of the original painting is dis tinctly retained, as in Pleurotomaria (fig. 575), which displays wavy blotches, resembling the coloring in many recent Trochidse. Fig. 573. Fiff. 574. Fig. 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: 1256px × 1991px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, booksubjectgeology, bookyear1868
