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Show 300 MR. F. E. BEDDARD ON THE [Feb. 18, by the late W. A. Forbes, upon the dissection of which the following notes are based. As to external characters, the pterylosis offers no salient point of difference from that of the Gulls as described by Nitzseh. The oil-gland is tufted. There are 12 rectrices. The bird is aquinto-cubital. As regards the alimentary viscera the most important fact to comment upon is the rudimentary and nipple-like character of the caeca. The tensores patagii are illustrated in the drawing exhibited (woodcut, fig. 1). They are exactly like those of Rissa tridactyla, Fig. 1. Muscles of the patagium of Rhynchops. t.p.l., tendon of tensor patagii longus; t.p.b., tensor patagii brevis; B, its wrist-ward slip; F, patagial fan ; A, tendinous threads on ulnar side of arm. of which I possess a drawing by Mr. W. A. Forbes. There are two tendons to the tensor brevis, of which the anterior is for the greater part of its length made up of three separate strands. The hinder tendon is much slighter. The anterior tendon gives off a little way from the forearm a wristward slip (fig. 1, B ) , from which, where it joins the tendon of the extensor radialis metacarpi, a patagial fan (F) arises which joins the longus. This fan as well as the main tendon of the brevis are continued over to the ulnar side of the forearm as a diffuse glistening tendon. From the point where the wristward slip of the brevis springs there is another connection with the longus, which is lettered A in the drawing (fig. ! )• |