On a New Species of Edestus from the Upper Carboniferous of Yorkshire

Abstract
The remarkable Upper Palæozoic fossil Edestus has already been proved to represent a row of symphysial teeth of an Elasmobranch fish, but it has hitherto been found only once in direct association with portions of jaws. A second specimen, still more instructive, has now been obtained by the Geological Survey from the upper part of the Millstone Grit at Brockholes, near Huddersfield, and I am indebted to Dr. Aubrey Strahan and Dr. F. L. Kitchin for the opportunity of studying it. The circumstances of its discovery are described in the Appendix by Mr. John Pringle. The new fossil, shown of two-thirds the natural size in Pl I, fig. 1, displays a single example of Edestus , with a detached dental crown and another fragment of the same form, near the tapering ends of a symmetrical pair of cartilages ( c ) which evidently represent a jaw. Whether they are upper or lower is uncertain, on account of the shortness of the portions preserved; but, as the anterior ends suddenly begin to taper and eventually become very slender, they are probably the pterygo-quadrates of the upper jaw. The cartilage is well calcified in very small tesseræ, and, as shown both by the portions of jaws themselves and by remains in front of the fossil, the calcification penetrates more deeply than is usual in recent Elasmobranchs. The best-preserved outer surface of the cartilage, on the side of the specimen not shown in the figure, is slightly marked with scattered fine pittings, such as have already

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