. Outlines of zoology. Zoology. â Mff. Fig. 159.âBivalve (Panopcea norvegica), showing siphons. e., Exhalant aperture ; /., inhalant aperture. mantle cavity. A similar but unpaired siphon is found in many Gasteropods. In Scaphopoda the mantle folds fuse ventrally to form a continuous tube. In most Gasteropods the mantle skirt is retained, and secretes a spiral shell, as well as enclosing a space in which the gills lie; in some, both mantle and shell are absent. In 'the snail and its allies (Pulmonata), the mantle fuses with the body-wall and forms the pulmonary chamber, which opens to the ante
. Outlines of zoology. Zoology. â Mff. Fig. 159.âBivalve (Panopcea norvegica), showing siphons. e., Exhalant aperture ; /., inhalant aperture. mantle cavity. A similar but unpaired siphon is found in many Gasteropods. In Scaphopoda the mantle folds fuse ventrally to form a continuous tube. In most Gasteropods the mantle skirt is retained, and secretes a spiral shell, as well as enclosing a space in which the gills lie; in some, both mantle and shell are absent. In 'the snail and its allies (Pulmonata), the mantle fuses with the body-wall and forms the pulmonary chamber, which opens to the anterior by a small aperture. In Cephalopoda the mantle skirt is well developed and muscular, and, besides sheltering the gills, is of much importance in locomotion. Typically the Molluscaare bilaterally symmetrical animals, and this symmetry is marked in the Amphineura, the Lamellibranchiata, and occurs to a less extent in the Cephalopoda (cf. the unpaired genital organs). In the. 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 Thomson, J. Arthur (John Arthur), 1861-1933. Edinburgh, Glasgow and London, H. Frowde and Hodder & Stoughton
Size: 1603px × 1559px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorth, bookcentury1800, bookdecade1890, booksubjectzoology
