. Elementary text-book of zoology. Zoology. 136 PISCES. of the praeoperculum constitute the branchial operculum, and are distinguished as operculum, suboperculum, and interoperculuni. A bone extending from the metapterygoid and quadrate to the upper jaw corresponds to the pterygoid, and is, as a rule, formed of an external (ectopterygoid) and an internal piece (endopterygoid). Then come the palatine bone and the apparatus of the upper jaw, with the prsemaxilla (intermaxilla), which is placed at the front of the snout and is usually moveable, and the very variable, usually tooth- less maxilla.
. Elementary text-book of zoology. Zoology. 136 PISCES. of the praeoperculum constitute the branchial operculum, and are distinguished as operculum, suboperculum, and interoperculuni. A bone extending from the metapterygoid and quadrate to the upper jaw corresponds to the pterygoid, and is, as a rule, formed of an external (ectopterygoid) and an internal piece (endopterygoid). Then come the palatine bone and the apparatus of the upper jaw, with the prsemaxilla (intermaxilla), which is placed at the front of the snout and is usually moveable, and the very variable, usually tooth- less maxilla. The two limbs of the lower jaw are only rarely fused together in the middle line, and are divided at least into a posterior. FIG-. 587.—Hyoid apparatus and branchial arches of Pereajluvialilis (regne animal). I, hyoid apparatus ; II—V, branchial arches; a, I, c, d, joints of the branchial arches, the upper joints (Ops) are the superior pharyngeal bones (pharyngo-branchials); I"/, (Opi) the inferior pharyngeal bones (reduced 5th branchial); Cop, copula?; Eb, branchiostegal rays. OS articulare and an anterior dentary; there may, however, also be an angulare and an operculare. Behind the mandibular arch there follows a system of equivalent arches surrounding the pharyngeal cavity. Of these the anterior— the hyoid arch—bears on its outer edge a number of cartilaginous rods, which serve to support the opercular membrane and are called the branchiostegal rays (fig. 587, Rl>], while the remaining arches are the branchial arches and serve for the support of the branchial lamella? (fig. 587). In the Teleosteans four (seldom three) arches bear gills, while the posterior arch is reduced so that only its ventral. 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 Claus, Carl, 1835-1899; Sedgwick, Adam, 1854
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1884
