File:Bulletin - United States National Museum (1920) (20496984952).jpg

Title: Bulletin - United States National Museum
Identifier: bulletinunitedst1101920unitfo (find matches)
Year: 1877 (1870s)
Authors: United States National Museum; Smithsonian Institution; United States. Dept. of the Interior
Subjects: Science
Publisher: Washington : Smithsonian Institution Press, (etc. ); for sale by the Supt. of Docs. , U. S. Govt Print. Off.
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Smithsonian Libraries

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Text Appearing Before Image:
OSTEOLOGY OF CARIv^IVOROUS DINOSAURS. 21 III front of the superior process the concave upper border contributes to the boundary of the narial opening and to a considerably greater degree than in Ceratosaurus. Posterior to the base of the ascending process the maxilhiry narrows rapidly in width to the obtusely pointed posterior end, which underlaps and unites by squamous suture with the anterior end of the jugal. Viewed from the side the dental border is slightly sinuous. The lower external surface is perforated by a considerable number of foramina. The larger foramina appear to arrange themselves in two rows, an upper curved row that in going forward ascends one-third the height of the bone, and a lower row that parallels the alveolar border (fig. 2, pi. 4). Between these rows, and irregularly placed, are numerous smaller foramina, and forward of the curved row, which stops beneath the second antiorbital fenestra, scattered foramina are observed nearly to the top of this portion of the maxillary.
Text Appearing After Image:
Fig. 12.—Left maxill\ry of Antiiodemu.s valens Leidy. No. i7:n, U.S.N.M. Internal view. J nat. size. /", Second ANTIORniTAL fenestra; jr, GROOVES FOR BLOOD VE.SSELS; 713, EXTENT OFUNIONWITH NASAL BONE; pmjT, END JOINING PREMAXILLARY. The general form and appearance of the maxillary when detached from the'sur- rounding elements is well shown in figure 12. On the internal side (fig. 12) some 2.5 mm., superior to the aveolar bo.rder on the anterior end and apjjroaching withing 5 mm. at the posterior end, is a row of small dental foramina. These foramina are at the bases of the interdental plates and are connected by nutrient grooves (gr, fig. 12). The interdental plates have their internal surfaces consideralily roughened, and they shorten dorso-ventrally from the front toward the back. On the upper border of the internal side, on the anterior half of the maxillary, a strong shelf of bone projects inward, the anterior end of this shelf projecting some distance in front of the maxillo-premaxillary 14403.5—20 ,S

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