Now that the tang for the hilt had been cast in one piece with the blade, and the attachment of the hilt no longer depended solely on the row of rivets at the butt of the blade, there was no necessity for this butt to be of so great a breadth. As a result we find in Type B the butt has become approximately semi-circular, with the horizontal and vertical radii equal. The flange on the sides of the tang remained, though in some cases it became lighter and not so sharply modelled. The blades of this type usually diminish gradually from below the butt to the point, but occasionally we find a slight broadening of the blade into the true leaf-shaped form. The numerous parallel grooves of Type A disappear, and in their place appear a few, generally three, narrow grooves, very close together, parallel to both sides of the blade, and dividing it into three almost equal strips. Towards the butt these grooves bend outwards to the edge, forming an almost perfect quadrant. Sometimes these grooves are combined into one, and result in sharp lines dividing the blade into three; in these cases the central third is much thicker than the two sides, and the section is not unlike that of a spear-head. Occasionally we find these parallel lines entirely absent, and the blade sloping to a median ridge, thus forming in section a rhomboid with concave sides; this variant is more common in the north, and seems to be a later local development. Types C and D are at first sight very much alike, but a close examination of the critical part will explain the difference. We have seen how in passing from Type A to Type B the horizontal radii diminish until they equal the vertical; in Type C the vertical has increased until it exceeds the horizontal, and an oval butt has developed. The curves in this case seem to be nearly if not exactly those of an ellipse. The flanges on the tang are still present, but tend to disappear before reaching the point at which the butt passes into the blade. The blades of this type sometimes retain their parallel sides, but more often the breadth expands, usually about halfway between the butt and the point. The lines of parallel grooving are tending to disappear; they have been reduced as a rule to a single line on either side, and although these are sometimes found in the same position as in Type B, dividing the blade vertically into three equal strips, it is more often the case that these lines have been moved nearer to the edge, which in some cases they approach as close as fifty millimetres. The blades in this type are relatively flat and thin, but the thickness diminishes considerably outside the parallel lines. These lines, in fact, are only indications of the place where the diminished thickness begins abruptly. In other cases the section is spindle-shaped. [Illustration: FIG. 15. SPINDLE-SHAPED SECTION.]