. An introduction to zoology, with directions for practical work (invertebrates). Fig. 72.—Bithynia tentaculata. A, Snail extended, showing operculum; B, eggs ; C, closed shell seen from below. being surrounded by a definite hexagonal area of jelly (see Fig. 72). Bithynia tentaculata.—Shell ^ inch long and with 6 whorls; aperture of shell oval. This is rare in the north of England. Bithynia Leachii. — Shell ^ inch long and with only 4 whoris, also the whorls are more rounded; aperture of shell nearly round. This form is only found in the south of England. Marine Univalve Fig. 73.—Th
. An introduction to zoology, with directions for practical work (invertebrates). Fig. 72.—Bithynia tentaculata. A, Snail extended, showing operculum; B, eggs ; C, closed shell seen from below. being surrounded by a definite hexagonal area of jelly (see Fig. 72). Bithynia tentaculata.—Shell ^ inch long and with 6 whorls; aperture of shell oval. This is rare in the north of England. Bithynia Leachii. — Shell ^ inch long and with only 4 whoris, also the whorls are more rounded; aperture of shell nearly round. This form is only found in the south of England. Marine Univalve Fig. 73.—The Common Periwinkle. Genus Littorina. Periwinkles. One species of this genus is Littorina Uttwalis, the common Periwinkle, very similar in structure and habits to Paludina, ' The name means "inhabiting deep water," but it is rather misleading, as this snail lives in poncls with Limnaea and 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 Lulham, Rosalie Blanche Jermaine. London, Macmillan
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondo, bookyear1913
