Elements of geology, or, The Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments elementsofgeolog00lyel Year: 1868 m Orthis tricenaria, Hall. New York. Canada. | nat. size. Orthis vespertilio, Sotv. Shropshire; N. and S. Wales. i nat. size. Strophomena (Orthis) grandis, Sow- erby. f nat. size. Horderly, Shropshire ; also Coniston, Lancashire. Burmeister, in his work on the organization of trilobites, supposes them to have swum at the surface of the water in the open sea and near coasts, feeding on smaller marine animals, and to
Elements of geology, or, The Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments elementsofgeolog00lyel Year: 1868 m Orthis tricenaria, Hall. New York. Canada. | nat. size. Orthis vespertilio, Sotv. Shropshire; N. and S. Wales. i nat. size. Strophomena (Orthis) grandis, Sow- erby. f nat. size. Horderly, Shropshire ; also Coniston, Lancashire. Burmeister, in his work on the organization of trilobites, supposes them to have swum at the surface of the water in the open sea and near coasts, feeding on smaller marine animals, and to have had the power of rolling themselves into a ball as a defence against injury. He was also of opinion that they underwent various transformations analogous to those of living crustaceans. M. Barrande, author of an admirable work on the Silurian rocks of Bohemia, confirms the doctrine of their metamorphosis, having traced more than twenty species through different stages of growth from the young state just after its escape from the egg to the adult form. He lias followed some of them from a point in which they show no eyes, no joints to the body, and no distinct tail, up to the complete form with the fall Fig. 647. Young individuals of Trinucleus concentricus (T. ornatus, Barr). a. Youngest state. Natural size and magnified; the body rings not at all developed. &. A little older. One thorax joint. c. Still more advanced. Three tho- rax joints. The fourth, fifth, and sixth segments are successively produced, probably each time the animal moulted its crust.
Size: 1829px × 1093px
Photo credit: © Bookworm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
