. Zoology : for students and general readers . Zoology. HABITS OF SEA URCHINS. 117 Class III.—Echiitoidea (Sea-urcliins). General Characters of Sea-Urchins.—A good idea of the general structure of the members of this class may be obtained by an examination of the common sea-ur- chin, Echinus (Fig. 78), of the eastern coast of the United. Fig. 78.—The common Sea-urchin, Echinvs (Strongyiocentrotue) drSbachlemis. d, frame-work of mouth and teeth seen in front; c, the same seen sideways; a, d, side and external view of a single tooth (pyramid); ail natural size.—After Morse. States, Northern Euro
. Zoology : for students and general readers . Zoology. HABITS OF SEA URCHINS. 117 Class III.—Echiitoidea (Sea-urcliins). General Characters of Sea-Urchins.—A good idea of the general structure of the members of this class may be obtained by an examination of the common sea-ur- chin, Echinus (Fig. 78), of the eastern coast of the United. Fig. 78.—The common Sea-urchin, Echinvs (Strongyiocentrotue) drSbachlemis. d, frame-work of mouth and teeth seen in front; c, the same seen sideways; a, d, side and external view of a single tooth (pyramid); ail natural size.—After Morse. States, Northern Europe, and the Arctic Seas. It is com- mon among rocks, ranging from low-water mark to fifty or more fathoms. It eats sea-weeds, and is also a scavenger, feeding on dead fish, etc. We have observed great num- bers of them assembled in large groups, feeding on fish offal, a few fathoms below the sur- face, in a harbor on the coast of Labrador, where fishing- vessels were anchored. On placing an Echinus in sea-water the movements of the animal, especially its mode of drawing itself along by its numerous long tenta- cles or ambulacral feet, and how it covers itself by draw- ing together bits of sea- weed and gravel, may be observed. A habit less easily detected is that of some sea-urchins burrowing in limestone rocks and coral reefs until the ani- mal sinks quite far down. How the rock becomes thus worn away, unless simply by the rotary movements of the body, is not clearly 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 Packard, A. S. (Alpheus Spring), 1839-1905. New York : Henry Holt
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1879
