. Bulletin of the British Museum (Natural History), Geology. 162 PALAEONISCOID FISHES AND THE CHONDROSTEI Diagnosis (emended). Fishes not exceeding 7 cm. in total length, body fusiform. Length of head contained four a half times, and greatest depth of body a little over four times, in total body length. Blade of maxilla rounded dorsally. Scales very finely denticulated posteriorly (far more denticulations than in D. insignis), with fine striations running up diagonally from these denticulations. These fine striae only on posterior third of scale ; anterior portion with few punctures and an occ
. Bulletin of the British Museum (Natural History), Geology. 162 PALAEONISCOID FISHES AND THE CHONDROSTEI Diagnosis (emended). Fishes not exceeding 7 cm. in total length, body fusiform. Length of head contained four a half times, and greatest depth of body a little over four times, in total body length. Blade of maxilla rounded dorsally. Scales very finely denticulated posteriorly (far more denticulations than in D. insignis), with fine striations running up diagonally from these denticulations. These fine striae only on posterior third of scale ; anterior portion with few punctures and an occa- sional stria following anteroventral margin (Text-fig. 14). Lectgtype, here chosen. and counterpart , a tolerably complete fish from the Deep Mine Ironstone (Westphalian C), Longton, Staffordshire. Material. In addition to the lectotype, five comparatively complete fish, four bodies without skulls, and isolated lower jaws in the British Museum (Natural History) and the Royal Scottish Museum. Description. The external skull bones including the jaws are ornamented with stout ridges of enamel, which are more or less contorted and not in straight lines as in D. insignis, Pseudogonatodus and Gonatodus. The orbit is large and the snout rounded. The suspensorium is upright and the lower jaw short and stout. The sutures between the frontals and between the frontals and parietals are digitate (Text-fig. 12). The maxilla is of characteristic shape (Text-fig. 13) with a larger. 3mm Fig. 13. Maxilla of Drydenius molyneuxi (Traquair). blade than in D. insignis. The coronoid bears large stout teeth as in D. insignis. The second infraorbital is expanded as in Pseudogonatodus parvidens and the infra- orbital canal much branched posteriorly as it passes through this bone. There are eleven branchiostegal rays and a median Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and app
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