. The sea-beach at ebb-tide : a guide to the study of the seaweeds and the lower animal life found between tidemarks . thefree and greatly extended type. Fig. B (page 413) illustrates theventral portion of a pelecypod, which shows very well the mostadvanced type of mantle the siphonal openingsat the end of the long projec-tion to the left, the only otheropening is the very small orificemarked 2, for the accommo-dation of a small, insignificantfoot. In the other figures dif-ferent degrees of mantle fusionare indicated. Before removing the mantlefrom one side of the specimento be
. The sea-beach at ebb-tide : a guide to the study of the seaweeds and the lower animal life found between tidemarks . thefree and greatly extended type. Fig. B (page 413) illustrates theventral portion of a pelecypod, which shows very well the mostadvanced type of mantle the siphonal openingsat the end of the long projec-tion to the left, the only otheropening is the very small orificemarked 2, for the accommo-dation of a small, insignificantfoot. In the other figures dif-ferent degrees of mantle fusionare indicated. Before removing the mantlefrom one side of the specimento be examined, note the twostrong muscles which are at either end of the body. These arethe anterior and posterior adductor muscles, their office being tohold the valves tightly shut. They are of great strength, as anyone may prove to his satisfaction by attempting to open a a long series of forms these two muscles approach eachother in position, and in the scallops and the oysters there is butone adductor muscle, occupying a central position. Morphologi-cally it is the survival of the posterior B
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmarinea, bookyear1901
