. Bulletin of the British Museum (Natural History), Geology. MIDDLE JURASSIC OSTRACODA FROM NORTH LINCOLNSHIRE 179 A considerable variation exists in the type of hinge exhibited amongst the podoco- pid ostracods. As a result it has been found convenient to name each distinct type (Moore, 1961 : 31-36). Among the species of the new genus Praeschuleridea, of which only a single species is described in the present paper, a characteristic hinge is present which is not typically paleomerodont, although at first glance it appears to be so. That type of hinge commonly attributed to the genus Schuleri
. Bulletin of the British Museum (Natural History), Geology. MIDDLE JURASSIC OSTRACODA FROM NORTH LINCOLNSHIRE 179 A considerable variation exists in the type of hinge exhibited amongst the podoco- pid ostracods. As a result it has been found convenient to name each distinct type (Moore, 1961 : 31-36). Among the species of the new genus Praeschuleridea, of which only a single species is described in the present paper, a characteristic hinge is present which is not typically paleomerodont, although at first glance it appears to be so. That type of hinge commonly attributed to the genus Schuleridea Swartz and Swain (Triebel, 1954), consists of terminal sockets connected by a median groove in the left valve and terminal teeth connected by a median bar in the right valve, the median bar projecting beyond the hinge line when viewed dorsally. In the hinge of Prae- schuleridea, however, it is the median element of the left valve which projects beyond the hinge line. In this respect the hinge is typically merodont and in possessing terminal loculate/dentate elements and smooth median elements conforms to the type known as hemimerodont. However, the terminal sockets of the left valve are united across the median bar by a smooth groove. In the right valve a low ridge connects the dentate terminal elements. The hinge is therefore partially hemimero-. 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). London : BM(NH)
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