The Transition from Rostro-Carinate Flint Implements to the Tongue-Shaped Implements of River-Terrace Gravels . lateral surface of this implementis given in fig. 4, and a comparison of this illustration with fig. 3b will show hownearly the profiles of the two rostro-carinates resemble each other. The author is of opinion that the sharp keel or carina of the rostro-carinateimplement was the object at which the ancient workmen were aiming. They requireda good cutting edge for various purposes, and the curving keel of the rostro-carinategave them what they wanted. In a paper published recently,^
The Transition from Rostro-Carinate Flint Implements to the Tongue-Shaped Implements of River-Terrace Gravels . lateral surface of this implementis given in fig. 4, and a comparison of this illustration with fig. 3b will show hownearly the profiles of the two rostro-carinates resemble each other. The author is of opinion that the sharp keel or carina of the rostro-carinateimplement was the object at which the ancient workmen were aiming. They requireda good cutting edge for various purposes, and the curving keel of the rostro-carinategave them what they wanted. In a paper published recently,^ the author has shownthat with the wish to provide a longer cutting edge the sharp keel was graduallycarried further and further back towards the posterior region of the implement, and <«. Journ. Eoy, Anthrop. vol. 46, pp. 197-220 (1916). 336 MR. J. E. MOIR: THE TRANSITION FROM ROSTRO-CARINATE FLINT IMPLEMENTS that this extension of the keel was accompanied, inevitably, by the reduction in sizeof the dorsal platform. He also drew attention to the fact that from the Pre-Crag Keel B Dorsalplatform. Fost. Fig. 4.—Left Lateral Face of Norwich Test Specimen. (Somewhat reduced in size.) period onwards the width of the ventral plane suffers a marked reduction. The Post-Crag rostro-carinates, in fact, show an ever-increasing tendency to be compressedfrom side to side. In the Middle Glacial Gravel of Suffolk, a deposit later in agethan the Red Crag, a series of rostro-carinates has been found which shows clearlythe characteristics above described. A diagrammatic drawing of one of these rostro-carinate implements from the Middle Glacial Gravel is given in fig. 5, and it will be seen Keel Keel i Dorsalplatform
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Keywords: ., bookcentury1900, bookdecade1920, bookidphiltrans003, bookyear1920
