. Bulletin of the British Museum (Natural History) Geology Supplement. ESPECIALLY MYCTOPHOIDS 87 ventro-laterally. The parasphenoid is visible beneath the orbit as an almost straight rod of bone with no lateral expansions. From the underside of the frontals, above the orbit, the lateral ethmoid is produced downwards and connects with the hind end of the palatine. The frontals bear an ornamentation of prominent ridges, the major ridges running longitudinally, especially above the orbit, and following the course of the supraorbital sensory canal. The mid-region of the frontals is smooth and unor
. Bulletin of the British Museum (Natural History) Geology Supplement. ESPECIALLY MYCTOPHOIDS 87 ventro-laterally. The parasphenoid is visible beneath the orbit as an almost straight rod of bone with no lateral expansions. From the underside of the frontals, above the orbit, the lateral ethmoid is produced downwards and connects with the hind end of the palatine. The frontals bear an ornamentation of prominent ridges, the major ridges running longitudinally, especially above the orbit, and following the course of the supraorbital sensory canal. The mid-region of the frontals is smooth and unornamented ; some small ridges appear above the sphenotic and pass laterally to the upper margin of the orbit. Infraorbital bones. The infraorbitals are shown in the lateral view of the skull, Text-figure 39. There are four narrow elongate infraorbitals and an elongated anterior lachrymal. The lachrymal is the largest bone in the series and is longer than deep. The antero-dorsal region of the lachrymal is produced dorsally, forming the anterior limit of the orbit. This dorsal projection articulates with the lateral ethmoid. Anteriorly and ventrally the lachrymal is expanded and overlaps the upper lateral region of the premaxilla. The ventral border of the lachrymal is slightly irregular in outline whilst the dorsal border is thickened and uniform. The infraorbital sensory canal was housed within a tube passing through each of the five bones which is incomplete in several places. On the lachrymal the sensory canal opened on to the surface of the bone in two places, anteriorly and antero-ventrally. The latter opening is in line with a groove on the lateral face of the premaxilla, which may have contained an anterior extension of the sensory canal. The lachry- mal is thickened along the course of the sensory canal and shows some evidence epo. Fig. 39. Enchodus marchesettii (Kramberger). Restoration of the skull in lateral Please note that these images are extracted from
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