. Revision of the Amphibia and Pisces of the Permian of North America. nt. The converg-ing posterior edges are thickened and the sculpture is carried out to theedge, making it somewhat rough. The anterior edges are thin where theywere overlapped by the clavicles. The sculpture radiates, in a general way,from a point somewhat posterior to the middle of the median line. In the bone beds, where the scattered bones of Trimerorhachis occurabundantly, mingled with remains of other creatures, a peculiarly formedplate is of very frequent occurrence; one such is shown in fig. 41 b. A similar plate is a
. Revision of the Amphibia and Pisces of the Permian of North America. nt. The converg-ing posterior edges are thickened and the sculpture is carried out to theedge, making it somewhat rough. The anterior edges are thin where theywere overlapped by the clavicles. The sculpture radiates, in a general way,from a point somewhat posterior to the middle of the median line. In the bone beds, where the scattered bones of Trimerorhachis occurabundantly, mingled with remains of other creatures, a peculiarly formedplate is of very frequent occurrence; one such is shown in fig. 41 b. A similar plate is associated with one of Copes specimens of Trimero-rhachis and in specimen No. 4866 Amer. Mus., such a plate lies betweenthe lower jaws. It is uncertain whether these are the clavicles or whetherthey are protective plates normally gular in position. One edge is nearlystraight; from this the plate rises in a convex surface and contracts to anapex, which is curved toward the underside of the bone; the whole plate ismarked by a sculpture of lines radiating from the Fig. 41. A. T. insignis. Outline of a rib, showing posterior expansion of blade. No. 4675 Am. Mus. X J<. B. Trimerorhachis sp. Outer view of a plate found in the thoracic or gular region. No 125 (Field No.) Am. Mus. X K- C. Trimerorhachis sp. Lower view of a small skull, showing such a plate as is figured in B, in position as found. No, 4866 Am. Mus. X H- Under the No. 4720 Am. Mus. are collected three humeri closely simi-lar to a less perfect one associated with a skull of Trimerorhachis. Theends are turned at an angle of 45° to each other, hardly half as great as inEryops and Diadectes. The articular surfaces are hollow and imperfectly ossified, showing thepresence of a large amount of cartilage. The inner side of the proximal endis wider than the outer and the face descends somewhat on the side of thebone; the shaft narrows to a triangular section. The outer edge of this partis interrupted by a stout rugosit
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Keywords: ., bookcentury1900, bookdecade1910, bookidc, booksubjectpaleontology
