. Text book of zoology. Zoology. Glass 1. Grinoidea. 129 like the barbs of a feather. The dorsal surface is covered all over, even to the pinnules, with large, thick, calcareous plates, closely set together, forming in each arm a series of vertebra-like joints, and upon the body a calyx, in which the viscera are disposed. All these Fig. 86. Fig. Fig. 85. of Antedon rosacea at various stagea of development. 1 and 2 young free-swimming larvse; in the latter, considerable portions of the adult skeleton are already deposited. 3 larva shortly after fixation, g gaatrula-mouth, J) pedal
. Text book of zoology. Zoology. Glass 1. Grinoidea. 129 like the barbs of a feather. The dorsal surface is covered all over, even to the pinnules, with large, thick, calcareous plates, closely set together, forming in each arm a series of vertebra-like joints, and upon the body a calyx, in which the viscera are disposed. All these Fig. 86. Fig. Fig. 85. of Antedon rosacea at various stagea of development. 1 and 2 young free-swimming larvse; in the latter, considerable portions of the adult skeleton are already deposited. 3 larva shortly after fixation, g gaatrula-mouth, J) pedal disc, r body, s stalk.—After Wyville Thompson. Fig. 86. Another species of Antedon {Antedon Eschrichtii) X 4 ; in the sessile condition.—After Levinson. ossicles, which make up a considerable portion of the body, are calcifications of the dorsal wall. The stalk, too, is chiefly composed of a series of calcareous joints; the cirrhi, filiform, or rarely root- like or branched processes, frequently arise from it, and contain similar calcifications. In contradistinction to the dorsal, the ventral surface of both body and arms is usually soft and little calcified. The mouth lies centrally (rarely excentrically) on the ventral surface, and a short distance off is the anus at the tip of a small conical tube in one of the inter-radii. Five ciliated furrows, ambulacral grooves, radiate from the mouth, and if only. 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 Boas, J. E. V. (Johan Erik Vesti), 1855-1935; Boas, J. E. V. (Johan Erik Vesti), 1855-1935. Lehrbuch der Zoologie. London, Sampson Low, Marston
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1896
