. Bulletin of the British Museum (Natural History) Zoology. 82 GORDON J. HOWES process. Vomer thin, bluntly triangular with dependent rim of thin bone; two rows of long incurved teeth on either side, 12- 16 in outer, 6-7 in inner row. In both genera nasals equally developed as long, shallow troughs of thin bone situated on either side of ethmoid. 2. Orbital region: Macruronus (Figs 2;4). Frontals broadly triangular, each with irregular and indented anterior border. Posterolaterally, frontal contacts dermosphenotic which lies in a notch formed partly by the frontal margin. Bony channel of front
. Bulletin of the British Museum (Natural History) Zoology. 82 GORDON J. HOWES process. Vomer thin, bluntly triangular with dependent rim of thin bone; two rows of long incurved teeth on either side, 12- 16 in outer, 6-7 in inner row. In both genera nasals equally developed as long, shallow troughs of thin bone situated on either side of ethmoid. 2. Orbital region: Macruronus (Figs 2;4). Frontals broadly triangular, each with irregular and indented anterior border. Posterolaterally, frontal contacts dermosphenotic which lies in a notch formed partly by the frontal margin. Bony channel of frontal sensory canal broad with an extensive anterior opening communica- ting with nasal. There are two lateral openings, the anterior one opens by a medial foramen into a central cavity. The broad, canopy-like roof covering frontal canal rises dorso- medially as a strong crest which continues rising posteriorly to meet its partner anterior to their junction with supraoccipital. Frontals sink between the crests forming deep V-shaped central cavity (so-called mucous cavity). Posteromedially, frontal surface forms sloped platform between high medial crest and diagonal crest which provides posterior wall of sensory canal. Ventrally, frontals bear medially curved, con- verging lamina which form an open groove for olfactory tracts. Parietals are short and broad, without crests. Pterosphenoid small, oblong with short, somewhat medially curved, ventral processes which forms a dorsomedial support for trigeminal nerve tract (Fig. 4). Parasphenoid circular in cross-section, narrow in orbital region but deepening anteriorly where it meets lateral ethmoids; the shallow, long ascending processes curves outward to meet prootic, intercalar and basioccipital (Fig. 4). Merluccius has subrectangular frontals with gently convex margins above lateral ethmoids (Fig. 5). A strong crest runs diagonally from anterolateral margin to join its partner on the supraoccipital, forming a broad V. Medial wall of
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