. Bulletin of the British Museum (Natural History), Geology. NEOGENE FISHES FROM ASCP. ARTP 5 mm ASCP Fig. 12. Premaxillae of : A. L. niloticus, and B. L. rhachirhinchus (from paratype lot ). In both, the anterior end of the bone is seen from above to show the relationship of the articular and ascending processes. medially below the notch, then passes obliquely downwards and opens laterally near the base of the articular process. No trace of this foramen is found in any living species ; presumably in L. rhachirhinchus it provided a passage for a branch of the maxillary nerve and perha
. Bulletin of the British Museum (Natural History), Geology. NEOGENE FISHES FROM ASCP. ARTP 5 mm ASCP Fig. 12. Premaxillae of : A. L. niloticus, and B. L. rhachirhinchus (from paratype lot ). In both, the anterior end of the bone is seen from above to show the relationship of the articular and ascending processes. medially below the notch, then passes obliquely downwards and opens laterally near the base of the articular process. No trace of this foramen is found in any living species ; presumably in L. rhachirhinchus it provided a passage for a branch of the maxillary nerve and perhaps also for a blood vessel. In Lates niloticus a large blood vessel passes through the cleft between the ascending and articular processes, and several nerves pass outwards and downwards on the lateral face of the premaxilla. No specimen of a L. rhachirhinchus premaxilla is sufficiently complete for us to determine accurately the size of the posterior maxillary process ; where some of the process is preserved it seems to be lower than in other species. No bone can be identified as a supramaxilla. Dentary. Unlike the jaw bones described so far, the dentary in L. rhachirhinchus seems to depart but slightly from that bone in extant species. The only differences we could detect are the relatively longer openings to the lateral-line sensory canal and a relatively narrower dentigerous surface (Fig. 13). It must, however, be remembered that only the anterior portion of the dentary is preserved in our speci- mens. As with the premaxilla, the pattern of densely packed and small bones of attach- ment on the dentary suggests that the teeth and dental pattern were similar to those in living Lates species. Certainly there are no indications of an outer row of enlarged teeth like those on the dentary of Luciolates stappersi, nor of the few enlarged an- terior premaxillary teeth such as occur in the premaxilla of that species. Angulo-articular. Most specimens are incomplete, and comprise only
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