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Updated: June 28, 2025
In the seas of the Carboniferous time, we notice that the ancient life of the earth is passing away. Many creatures, such as the trilobites, die out, and many other forms such as the crinoids or sea lilies become fewer in kind and of less importance.
There animal life was represented by nothing more than sea lilies, starfish, delightful crinoids with bell-shaped heads like little chalices on straight stems, top-shell snails, blood-red tooth shells, and fissurella snails, a large species of coastal mollusk. By April 20 we had risen to an average level of 1,500 meters.
I should add, however, that many impressions described as produced by Worms are more likely to have been the tracks of Crustacea. But by far the most characteristic class of Articulates in ancient times were the Crustaceans. The Trilobites stand in the same relation to the modern Crustacea as the Crinoids do to the modern Echinoderms.
He would bring out a piece of rock and examine it, and say to himself, "It is limestone it has crinoids and corals in it the rock is right" Then he would throw it down with a sigh, and say, "But that is nothing; where coal is, limestone with these fossils in it is pretty certain to lie against its foot casing; but it does not necessarily follow that where this peculiar rock is coal must lie above it or beyond it; this sign is not sufficient."
It is represented in the present seas by the delicate and rare Pentacrinus caput-medusae of the Antilles, which, with Comatula, is one of the few surviving members of the ancient family of the Crinoids, represented by so many extinct genera in the older formations. Scales of Lepidotus gigas. Agass. a. Aechmodus Leachii and Dapedius monilifer. a. Aechmodus. Restored outline. b.
The Crinoids, with the closed cups in some, and the open, star-like crowns in others, unite features of the present Star-Fishes and Sea-Urchins, and, by their stem attaching them to the ground, include also a Polyp-like character; while the Trilobites, with their uniform rings and their prominent anterior shield, unite characters of Worms and Crustacea.
Besides the star-fish there occur abundance of those peculiar bodies called Cystideae. They are the Sphaeronites of old authors, and were considered by Professor E. Forbes as intermediate between the crinoids and echinoderms. With it have been found several other genera of the same family, such as Sphaeronites, Hemicosmites, etc.
The subjoined wood-cut represents one with a closed cup; but the number of their different patterns is hardly to be counted, and I would invite any one who questions the abundant expression of life in those days to look at some slabs of ancient limestone in the Zoölogical Museum at Cambridge, where the stems of the Crinoids are tangled together as thickly as sea-weed on the shore.
It was for a long time supposed that these wonderful creatures were extinct, but dredges have brought up from the dark depths of the sea actual living stone lilies, or crinoids, this being their real name. Few of us will probably ever have an opportunity of studying a crinoid alive, although in our museums we may see them preserved in glass jars.
Allusion has already been made to numerous zones in the Lias having each their peculiar Ammonites. Two of these occur near the base of the Lower Lias, having a united thickness, varying from 40 to 80 feet. Miller. 1/2 natural size. E. Forbes. Among the Crinoids or Stone-lilies of the Lias, the Pentacrinites are conspicuous. The remains are often highly charged with pyrites.
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