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 538 MIDDLE DEVONIAN. [Ch. XXVI. species), both in England and on the Continent. In Germany they are usually confined to distinct beds, as at Oberscheld, also at Couvin in Belgium, &c. Trilobites are not unfrequent in Cornwall; they are chiefly restricted to species of Phacops,. P. Icevis, &c, but in the upper Devonian limestones of the Fichtelgebirge, as at Elbersreuth in Bava- ria, there are numerous other genera a
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 538 MIDDLE DEVONIAN. [Ch. XXVI. species), both in England and on the Continent. In Germany they are usually confined to distinct beds, as at Oberscheld, also at Couvin in Belgium, &c. Trilobites are not unfrequent in Cornwall; they are chiefly restricted to species of Phacops,. P. Icevis, &c, but in the upper Devonian limestones of the Fichtelgebirge, as at Elbersreuth in Bava- ria, there are numerous other genera and species, such as Brontes, Cyphastis, &c, which never rise higher in the series or appear in any portion of the carboniferous limestone. Middle Devonian. The unfossiliferous series (No. 2, p. 536) of North Devon, and the calcareous beds of Ilfracombe (3), correspond to the Dartmouth and Plymouth groups of Prof. Sedgwick's South Devon series, and are the most typical portion of the Devonian system. They include the great limestones of Plymouth and Torbay, replete with shells, trilobites, and corals. A thick accumulation of slate and schist, full of the same fossils, occupies nearly all the southern portion of Devonshire and a large part of Cornwall. Among the corals we find the genera Favo- sites, Heliolites and Cyathophyllum, the last genus equally abundant in the Silurian and Carboniferous systems, the two former so frequent in Silurian rocks. Some few even of the species are common to the Devonian and Silurian groups, as, for example, Favosites polymorphs (fig. 605), one of the commonest of all the Devonshire fossils. The Cyathophyllum ccespitosum (fig. 606) and Heliolites pyriformis (fig. Fm. 605. Fig. 605. Favosites polymorpha, Goldf. S. Devon, from a polished specimen. a. Portion of the same magnified, to show the pores.
Size: 1800px × 1111px
Photo credit: © Bookworm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
