. A junior course of practical zoology. Zoology. SECTION THEOUGH PHAEYNX 185 B. Transverse Section through, the Anterior Fart of the Pharynx. 1. General characters. The section is triangular ia shape, the apex being formed by the dorsal fin, the base by the ventral surface, and the basal angles by the lateral fins. The pharynx, perforated by the gill-sUts, and surrounded by the atrial cavityj lies below the noto- Fig. 32.—Amphiozss lanceolatns. Transverse section through the anterior part of the pharynx of an adult specimen. The boundary of the atrial cavity is indicated by a thick bla
. A junior course of practical zoology. Zoology. SECTION THEOUGH PHAEYNX 185 B. Transverse Section through, the Anterior Fart of the Pharynx. 1. General characters. The section is triangular ia shape, the apex being formed by the dorsal fin, the base by the ventral surface, and the basal angles by the lateral fins. The pharynx, perforated by the gill-sUts, and surrounded by the atrial cavityj lies below the noto- Fig. 32.—Amphiozss lanceolatns. Transverse section through the anterior part of the pharynx of an adult specimen. The boundary of the atrial cavity is indicated by a thick black line. (a. m. m.) A) skeleton of dorsal fin, B, spinal cord. C. notochord. D. connective- tissue sheath surrounding notochord. E, cavity of pharynx. I", hyper- branchial groove of pharynz. G. hypobranchial groove of pharynx, which in this aniierior part is flattened out or even convex. H, atrial cavity. J^ trans- verse muscles in floor of atrial cavity. M, dorsal coelomic canal, P, meta- pleural coelomio canals. H, left dorsal aorta. S. cardiac aorta. 3^. myotome. 7, suspensory fold of pharynx, separating the dorsal coelomic canal from the atrial cavity. Z, gill-arch or branchial 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 Marshall, A. Milnes (Arthur Milnes), 1852-1893; Hurst, C. Herbert (Charles Herbert), 1856?-1898, joint author. London, Smith, Elder
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1887
