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Show 632 MR. A. SMITH WOODWARD ON SOME [Nov. 18, pct.)'\s not completely known, but its rays clearly exhibit the just described. Its supporting elements are attached to a long, slender, gently arched clavicle, externally marked with delicate, irregular longitudinal striations; and there is a large supraclavicle above this, adjoining the truncated angle of the operculum (s.cl.), broad above, tapering below, and transversely marked with numerous, closely arranged coarse rounded rugae of ganoine. The dorsal and anal fins are precisely opposed, not far from the caudal extremity, as shown in Plate LV. fig. 9, and the lobes of the deeply forked caudal fin (Plate LV. fig. 10) seem to be obtusely pointed, with a convex posterior- inner border, of which the subdivisions of the branched rays are extremely numerous and delicate. There are indications of minute fulcra on each of the median fins. Squamation.-The squamation is continuous, and all the scales are thick and bony, with a superficial layer of ganoine. They are slightly imbricating, and the posterior border is either smooth or feebly crimped. Except quite at the extremity of the tail, the greater part of the flank is covered by a single very deep longitudinal series of scales, along the upper part of which extends the lateral line, as indicated by the row of short transverse ridges by which its course is marked. In the anterior part of the trunk, one of these scales is between five and six times as deep as broad, abruptly truncated below, but somewhat tapering and slightly reflexed forwards above the position of the lateralline. On the inner face of the scale there is a vertical median ridge, terminating above in a feeble articular peg, and excavated below by a small socket. Into the latter fits the upper articular peg of another scale, two and a half times as deep as broad, which is slightly overlapped by the principal flank-scale, and is similarly strengthened by a prominent ridge within. The ventral margin is completed by three or four small scales, one above the other, as broad as those above, but having an extremely short vertical measurement. There are no indications of ventral ridge-scales. At the upper end of each principal flank-scale there occurs a rhomboidal scale scarcely twice as deep as broad, having a slight oblique ridge about its middle (Plate LIV., Plate LV. figs. 7, 8). Another nearly similar but less deep scale adjoins the anteriorly directed upper border of the latter ; and a small azygous ridge-scale (Plate LV. fig. 8, r.), irregularly sexangular, narrower in front than behind, completes the vertical series above. The writer has not observed any peg-and-socket articulation in these upper scales, and it is probable that their borders simply overlap. Towards the caudal region (Plate LV. figs. 9,10) the depth of the principal flank-scales becomes relatively less, while the very narrow ventral scales are more nearly equilateral ; at the extremity of the tail, indeed, all the scales are diamond-shaped and of nearly uniform dimensions. The scale ornament varies considerably in different individuals and upon different parts of the body, but it is essentially similar to that of the external head and opercular bones already described, though perhaps less prominent. In small (probably young) specimens, both the bones and scales are very feebly ornamented, but in fully grown individuals the rugose ganoine is always conspicuous. Each scale of the two |