. Outlines of zoology. two long connectives, andgiving off nerves to mantle, muscles, etc., andto a patch of smelling cells (psphradium) atthe bases of the organs.—Unlike not a few bivalves, which havehundreds of eyes on the mantle margin, Anodonta hasrio trace of any. The ear-sac, originally derived from a skin-pit, is sunk deeply within the foot, and is of doubtful smelling patch or osphradium at the base of thegills has perhaps water-testing qualities. There are also tactile cells about the mantle, labial palps, etc. Alimentary system.—The mouth lies between theanterior
. Outlines of zoology. two long connectives, andgiving off nerves to mantle, muscles, etc., andto a patch of smelling cells (psphradium) atthe bases of the organs.—Unlike not a few bivalves, which havehundreds of eyes on the mantle margin, Anodonta hasrio trace of any. The ear-sac, originally derived from a skin-pit, is sunk deeply within the foot, and is of doubtful smelling patch or osphradium at the base of thegills has perhaps water-testing qualities. There are also tactile cells about the mantle, labial palps, etc. Alimentary system.—The mouth lies between theanterior adductor and the foot, and beside it lie the ciliated,vascular, and sensitive labial palps, two on each side, which ALIMENTARY SYSTEM. 397 waft food into the mouth. It opens immediately into thegullet, for the pharynx of other Molluscs, with all itsassociated structures, is abseiit in Lamellibranchs. Theshort wide gullet leads into a large stomach surrounded bya paired digestive gland. Part of the food digested by. Fig. 214.—Structure ol Anodonta.—After Rankin. Anterior adductor; ^ cerebro-pleural ganglia; st.^stomach; 2/., ventricle, with an auricle opening into it; A.,kidney, above which is the posterior retractor of the foot;r., rectum ending above^posterior adductor; w.^., visceralganglia witli connectives (in black) from cerebro-pleurals ; g.^gut coiling in foot ; ^.^., pedal ganglia in foot, where also areseen branches of the anterior aorta and the reproductive organs;hp., labial palps behind mouth. At the posterior end the ex-halant (upper) and inhalant (lower) apertures are seen. these juices in the stomach is compacted in autumn into a crystalline style —a mass of reserve foodstuffs, and similarbut less solid material is found in the intestine. On thissupply the mussel tides over the winter. The intestine,which has in part a folded wall like that of the earthworm,coils about in the foot, asqends to the pericardium, passes 398 PHYLUM MOLLUSC A. thr
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Keywords: ., bookcentury1900, bookdecade1910, bookidcu3192, booksubjectzoology
