. Natural history of animals. Containing brief descriptions of the animals figured on Tenney's Natural history tablets, but complete without the tablets. Zoology. 220 RADIATES: ECHINODEEMS. faces. So much can these suckers be extended that a Sea-Urchin has been seen to put them forth from the top, and, bending them downwards, cling to the bot- tom of the basin in which the animal was lying! Fig- ure 463 shows a common kind of Sea-Urchin as it ap- pears when alive. When the animal dies, the skin, which covers the shell and holds the spines in their. iig. 464. — Top View of Sea-XJrchin. Spines r
. Natural history of animals. Containing brief descriptions of the animals figured on Tenney's Natural history tablets, but complete without the tablets. Zoology. 220 RADIATES: ECHINODEEMS. faces. So much can these suckers be extended that a Sea-Urchin has been seen to put them forth from the top, and, bending them downwards, cling to the bot- tom of the basin in which the animal was lying! Fig- ure 463 shows a common kind of Sea-Urchin as it ap- pears when alive. When the animal dies, the skin, which covers the shell and holds the spines in their. iig. 464. — Top View of Sea-XJrchin. Spines removed. places, dries up, and the spines fall oif, and then the shell, with all its beautiful structure and markings, is plainly seen. In the one represented in Figure 464 we find ten double rows of plates which run along the curved surface from the bottom to the top of the shell. In five of these double rows the plates are large, with- out holes, and are covered with large tubercles. Al- ternating with the doiible rows of large plates are five double rows of smaller ones, bearing few and small tubercles, and each plate is perforated with the holes for the suckers. The plates which bear the holes are called the ambulacral plates, — from a Latin word which means a walk, or alley; and the large plates without holes are called the inierambidaeral plates. At the termination of each of the five belts or zones of ambu- lacral plates there is a little triangular plate with a. 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 Tenney, Sanborn, 1827-1877; Tenney, Abby Amy (Gove) 1836-. New York, Scribner, Armstrong
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1875
