. The Cambridge natural history. Zoology. 592 ECHINODERMATA—CRINOIDEA. Fig. 271.—Pentacrinus asteria. X J. (From Wyville Thomson.) radial bears a pinnule. Pentacrinus is found in: both the Caribbean Sea and the Pacific Ocean; Metacrinus in the Pacific. It appears that the Pen- tacrinidae when young are attached by a foot- plate at the apex of the stem; but when adult, the stem is broken in two and the animals, like Antedon, swim by movements of the arms, dragging a large part of the stem after them, by which they effect tem- porary attachment. As in other stalked forms, the cavities of the cha
. The Cambridge natural history. Zoology. 592 ECHINODERMATA—CRINOIDEA. Fig. 271.—Pentacrinus asteria. X J. (From Wyville Thomson.) radial bears a pinnule. Pentacrinus is found in: both the Caribbean Sea and the Pacific Ocean; Metacrinus in the Pacific. It appears that the Pen- tacrinidae when young are attached by a foot- plate at the apex of the stem; but when adult, the stem is broken in two and the animals, like Antedon, swim by movements of the arms, dragging a large part of the stem after them, by which they effect tem- porary attachment. As in other stalked forms, the cavities of the chambered organ are prolonged into canals which traverse the stalk; but in this family there is the peculiarity that a repetition of the cham- bered organ is found opposite every whorl of cirri. Fam. 4. Holopodidae. —Stem represented by a leathery noncalcified outgrowth from the base of the calyx; one circle of radials indistinguish- ably fused with the basals and with each other to form the walls of the calyx. Large oral plates, ten short. 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 Harmer, S. F. (Sidney Frederic), Sir, 1862- ed; Shipley, A. E. (Arthur Everett), Sir, 1861-1927. ed. [London, Macmillan and Co. , Limited; New York, The Macmillan Company
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
