. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. PISCES. 961 which does not exist at all upon the opposite side of the head, while anteriorly the anterior frontals (2) and the nasal bone (20) complete this part of the face. An orbital cavity is thus constructed upon the right or upper side of the head of the Ijleuronectida3, which suffices for the lodgment of the two eyes, which thus take the only position in which both could be made useful.* Another equally remarkable arrangement is observable in the construction of the jaws of the Pleuronectidee, which are in many ge
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. PISCES. 961 which does not exist at all upon the opposite side of the head, while anteriorly the anterior frontals (2) and the nasal bone (20) complete this part of the face. An orbital cavity is thus constructed upon the right or upper side of the head of the Ijleuronectida3, which suffices for the lodgment of the two eyes, which thus take the only position in which both could be made useful.* Another equally remarkable arrangement is observable in the construction of the jaws of the Pleuronectidee, which are in many genera very unequally developed on the two sides of the median line, only in this case the prepon- derance of developement is just the reverse of what exists in the orbital portion of the face, for here the bones of the right or upper side are small, while those of the left or inferior half are of considerably greater size and strength. Moreover, the former are but sparingly fur- nished with teeth, while the latter support the chief part of the dental apparatus; so that by this structure the mouth becomes twisted toward the ground, and the teeth so disposed as to work most effectually in that direction. In the Syngnathidae, Ostracions, and other Fishes, where the exoskeleton is inordinately developed, so as to form a suit of bony armour in which the exterior of the body is completely covered, the endoskeleton is proportionately weak and imperfectly formed, many of the Fig. bones remaining in a rudimentary condition. This is well seen in the osteology of the Fly- ing Hippocamp, (Pegasus draco, fig. 494,) where the bones both of the head and trunk seem to perform quite a secondary part as contrasted with the dense tegumenlary frame- work covering the body. The whole face seems " The above description of the structure of the face in the Pleuronectidas is derived from a disarti- culated skull of the Halibut, contained in the Mu- seum of the Royal College of Surgeons in Lo
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