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We had the crinoid alive for ten or twelve hours. When contracted, the pinnules are pressed against the arms, and the arms themselves shut against one another, so that the whole looks like a swash made up of a few long, coarse twines.
The position of the pinnules on both sides of the central stalk are seen in the fossil to be shaped something like a comb, or a saw, whilst up the centre of each pinnule the vein is as prominent and noticeable as if the fern were but yesterday waving gracefully in the air, and but to-day imbedded in its shaly bed. Pecopteris Serlii.
I have not been able to detect any motion in the stem traceable to contraction, though there is no stiffness in its bearing. When disturbed, the pinnules of the arms first contract, the arms straighten themselves out, and the whole gradually and slowly closes up.
When the animal opens, the arms at first separate without bending outside, so that the whole looks like an inverted pentapod; but gradually the tips of the arms bend outward as the arms diverge more and more, and when fully expanded the crown has the appearance of a lily of the L. martagon type, in which each petal is curved upon itself, the pinnules of the arms spreading laterally more and more, as the crown is more fully open.
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