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Show 658 MR. A. SMITH WOODWARD ON THE SO-CALLED [Nov. 20, below the angle there extends the sensory canal, opening by a series of pores (seen in Brit. M u s . nos. 4294, P. 6456). There are two large postorbital cheek-plates (fig. 3, pt.o.), thinner than the other external bones (except the gular plate), and there are also remains of suborbitals extending to the anterior border of the preoperculum. The opercular apparatus is complete and the bones are robust. The operculum (fig. 3, op.) is trapezoidal in form, about two-thirds as broad as deep, and marked with coarse branched rugae radiating from the point of suspension. The suboperculum (fig. 3, s.op.), likewise ornamented, is almost sickle-shaped and deeply overlapped by the operculum, and bears a large ascending process at its antero-superior angle. The interoperculum is small, smooth, and much overlapped. The preoperculum (fig. 3, p.op.) is sharply angulated and marked with radiating rugae. There are not less than eighteen branchiostegal rays (as shown by B.M. no. P. 5680), the uppermost large, broad, and rugose; and five of these are supported by the epihyal. In advance of the branchiostegal rays, between the rami of the mandible, there is also a conspicuous gular plate (fig. 1, gu.), remarkably thin and elongated, but shown both in the specimen figured and in others in the British Museum numbered 4207, 4296, 4299, and 49891. The axis of the trunk is only imperfectly known. _ The vertebral centra are strengthened by secondary calcifications in the form of small irregular longitudinal ridges; those of the anterior abdominal region and the hinder caudal region are deeper than long, while the remainder are about as long as deep. Ribs are observable, and there are much thickened neural and haemal arches fused with the centra towards the base of the tail (B.M. no. 4303). Some styli-form bones in the abdominal region of no. 49892 also appear to be intermuscular elements. There is nothing worthy of remark in the pectoral arch, of which the long supraclavicle and relatively large and smooth clavicle are shown in a British Museum specimen, no. P. 5680. The pectoral fin-rays (fig. I, pet.) are unjointed for a considerable distance proximally, and the foremost ray (shown in B.M. no. 49894) exhibits an oblong expansion at its base of attachment. The rays of the pelvic fins (fig. 1, plv.) are not less than 11 in number and are similarly only divided quite at the distal end; their supporting elements are unknown. The dorsal fin, placed in the middle of the back, opposite to the pelvic pair and arising somewhat in advance of the latter, is incompletely known, but consists of robust rays unjointed for a long distance proximally, very closely divided at the distal end; the supports (shown in B.M. no. 49892) are large and dagger-shaped, having wide "wings." The anal fin (fig. 1, a.) is small and remote; the caudal fin appears to have been forked (B.M. no. 49891). The scales are very deeply overlapping, the covered portion being marked by few radiating grooves terminating at the anterior truncated margin. The posterior border is gently rounded, and |