. Elements of comparative anatomy. Anatomy, Comparative. SKULL OF VERTEBRATA. The covering bones are : the and Aves), or unpaired (Ophi- dii, Saurii, Orocodilini) (Fig. 248, Fa). The frontal also is unpaired in most of the Saurii, and in the Orocodilini (Fig. 248, B Fr). It is paired in Lacerta and Monitor (Fig. 248, A Fr), and in the Ophi- dii, Ohelonii, and Aves. Iu the Reptilia the postfrontals limit the posterior edge of the orbit (Figs. 248, Ff; 249, BCPf). In the middle of the ethmoidal region there is a considerable remnant of the primordial cranium (Ohelonii). The lateral ethmoids
. Elements of comparative anatomy. Anatomy, Comparative. SKULL OF VERTEBRATA. The covering bones are : the and Aves), or unpaired (Ophi- dii, Saurii, Orocodilini) (Fig. 248, Fa). The frontal also is unpaired in most of the Saurii, and in the Orocodilini (Fig. 248, B Fr). It is paired in Lacerta and Monitor (Fig. 248, A Fr), and in the Ophi- dii, Ohelonii, and Aves. Iu the Reptilia the postfrontals limit the posterior edge of the orbit (Figs. 248, Ff; 249, BCPf). In the middle of the ethmoidal region there is a considerable remnant of the primordial cranium (Ohelonii). The lateral ethmoids (pre- frontals) bound the anterior edge of the orbit in Reptiles; in Birds they appear to be connected with the median portion of the ethmoid. The vomer is paired in the Ophidii and Saurii (Fig. 250, Vo). The nasals are almost always absent from its upper surface in the Ohelonii, and in some of the Saurii. A new covering bone which is seen on the outer face of the ethmoidal capsule is Saurii, Orocodilini, and Aves (Fi parietals, which are paired (Ohelonii. Pig. 248. Skull of Reptilia; seen from above. A Monitor. B Crocodile. Os Supra- occipital. C Occipital Condyle. Pa Parietal. Pf Postfrontal. Fr Frontal. Prf Pre-frontal. L Lachrymal. N Nasal. Sq Scmamosal. Qj Quadratojugal. Jit Jugal. Q Quadrate. Mx Maxilla. Px Premaxilla. co Columella. the lachrymal; it is found in most gs. 248, 240, L). § 348. The anterior portion of the primitive palato-quadrate cartilage undergoes atrophy very early, so that the bones which belong to it are partly "developed on the skull itself. The hinder portion of the palato-quadrate persists as the quadrate (Fig. 249, Q). The quadrate is movable in the Saurii, Ophidii, and Aves, while in the Ohelonii and Orocodilini it is firmly united to the skull. The whole complex of bones, which is differentiated in the palato- quadrate cartilage, is intimately and immovably connected with the cranium, while, when the quadrate bone is movable, some, at leas
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectanatomycomparative
