. Elements of geology : a text-book for colleges and for the general reader. Geology. Fig. 331. Fig. 332. Figs. 327-332.—Silurian Crinoids: 327. Caryocrinus ornatus. 328. Pleurocystitis squamosus. 329. Pseudocrinus—a cystid restored (after Lutken). 330. Lepadocrinus Gebhardii. 331. Glyp- tocrinus decadactylus (after Hall): a, specimen with arms; b, larger specimens without the arms. 332. Ichthyocrinus sublasvis (after Hall). upon a stalk, the Cystids and Blastoids may be compared to Sea-urchins similarly set. All these families are found in the Silurian. The Cys- tids pass away with the Siluri
. Elements of geology : a text-book for colleges and for the general reader. Geology. Fig. 331. Fig. 332. Figs. 327-332.—Silurian Crinoids: 327. Caryocrinus ornatus. 328. Pleurocystitis squamosus. 329. Pseudocrinus—a cystid restored (after Lutken). 330. Lepadocrinus Gebhardii. 331. Glyp- tocrinus decadactylus (after Hall): a, specimen with arms; b, larger specimens without the arms. 332. Ichthyocrinus sublasvis (after Hall). upon a stalk, the Cystids and Blastoids may be compared to Sea-urchins similarly set. All these families are found in the Silurian. The Cys- tids pass away with the Silurian, and are therefore characteristic of that age. The Blastoids pass away before the end of the Carbonifer- ous age, and are therefore characteristic of the Palaeozoic era, but espe- cially of the Devonian and Carboniferous ages. The distribution of the three orders in time is shown in diagram (Fig. 326). The Crinids continue, though in diminished numbers, to the present day; but of course in very different families. Figures of Blastoids are given under the Carboniferous, where they were far more 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 LeConte, Joseph, 1823-1901. New York : D. Appleton and Co.
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