. Bulletin of the British Museum (Natural History), Geology. 268 EVOLUTION OF THE SNOUT IN ACTINOPTERYGIANS Ssc. Fig. 2. Cosmoptychius striatus (Agassiz). Reconstruction of skull in lateral view. The skull is characterized by its oblique suspensorium and the make up of the opercular apparatus. The suprascapulars are stout, bluntly rounded posteriorly and joined to a single pair of narrow extrascapulars. The parietals are small and square and the greater portion of the skull roof is made up by the large rectangular frontals. The dermopterotics are small and do not extend far enough to meet the
. Bulletin of the British Museum (Natural History), Geology. 268 EVOLUTION OF THE SNOUT IN ACTINOPTERYGIANS Ssc. Fig. 2. Cosmoptychius striatus (Agassiz). Reconstruction of skull in lateral view. The skull is characterized by its oblique suspensorium and the make up of the opercular apparatus. The suprascapulars are stout, bluntly rounded posteriorly and joined to a single pair of narrow extrascapulars. The parietals are small and square and the greater portion of the skull roof is made up by the large rectangular frontals. The dermopterotics are small and do not extend far enough to meet the nasals anteriorly. The postrostral is a stout ossification whilst the nasals are thinner and more delicate. Ventrally the nasals join the toothed antorbital and there is some evidence of a rostro-premaxillary bone in front of the antorbital and beneath the postrostral. The snout is bluntly rounded ( and counterpart). There are but two members of the infraorbital series. The first is short and rectangu- lar joining the antorbital anteriorly and the maxilla ventrally. The second infra- orbital has an expanded basal portion which is concave posteriorly where it fits under the suborbital series. Dorsally the second infraorbital meets the dermos- phenotic. The dermosphenotic forms the upper posterior margin to the orbit and extends forwardly just to meet the frontal. The suborbital series consists of two bones, the lower of which is the larger ; both are approximately triangular in outline ( ). Occasionally these two bones are fused into a single ossification ( ). The maxilla is of the normal palaeoniscoid pattern and curves slightly upwards before it meets the antorbital. The 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 British Museum (Natural History
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