. A textbook in general zoology. Zoology. lie CLAMS, , AND MUSSELS foot (Fia;. 62). The head bears two feelers, or tentacles, Phj'sa lays its eggs in February or March, in bean-shaped, transparent, gelatinous masses, on leaves or sticks in the water. Lininfea lays fewer eggs in a mass, and lays them later in the spring. Besides Linmica and Physa, the snails that belong to the genera Planorbis and Paludina are commonl}' known as "pond ; The members of the former genus have shells coiled in a flat spiral, like a roll of tape, and breathe air directly, like Limntea. The m
. A textbook in general zoology. Zoology. lie CLAMS, , AND MUSSELS foot (Fia;. 62). The head bears two feelers, or tentacles, Phj'sa lays its eggs in February or March, in bean-shaped, transparent, gelatinous masses, on leaves or sticks in the water. Lininfea lays fewer eggs in a mass, and lays them later in the spring. Besides Linmica and Physa, the snails that belong to the genera Planorbis and Paludina are commonl}' known as "pond ; The members of the former genus have shells coiled in a flat spiral, like a roll of tape, and breathe air directly, like Limntea. The members of the latter genus have, generally, a longer and more pointed shell and breathe by means of gills, much like an oyster. Helix. —The common garden snail will serve well as an example of the genus Helix (Fig. 63). It has a horn-coloreil shell within which it can contract the whole body. It has two eyes, one at the end of each of the large tentacles. It breathes by means of a lung which communicates with the outside by an opening in the side of the snail's neck that can be closed or opened at will. This snail lives on plants. In France, some memliers of the genus, Helix, somewhat larger than our own ganlen snail, are extensively eaten as food. Slugs.— ai-e snails that have no visible shell,— in fact, some of them haA'e none at all. They usually feed only in the night time, hence are not often seen. One, which is sometimes found crawling along roads or walks, is known. Fig. 63 - Garden 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 Herrick, Glenn W. (Glenn Washington), 1870-1965. New York, Cincinnati [etc. ] American Book Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectzoology, bookyear1912
