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Show 596 DR. R. BROOM ON A SOUTH AFRICAN [May 29, of the bone is about 34 mm. Both the upper and lower ends are broad, and they make with each other an angle of about 60°. The delto-pectoral ridge is fairly well developed, but the imperfect impression does not show very clearly its relations to the shaft. There is apparently no epicondylar foramen. The lower end of the bone measures about 10 mm. It has evidently been capped by a large pad of cartilage. Pelvis. The remains in specimen 0 are much better preserved than in either A or B. All the pelvic bones are preserved and in almost true apposition. The under and outer sides of both pubes and iscliia have been displayed, and the inner side of the right ilium. The pelvis is a slightly modified variety of the well-known plate-like type found in all primitive Diaptosaurian reptiles. The ilium is broad and flat, and its axis is directed upwards and backwards from the acetabulum. It is presumed that the acetabulum is of large size from the shape of the lower part of the ilium, and probably it had a thick coating of cartilage. The acetabular portion of the ilium measures 19 mm. across. Above the acetabulum the bone becomes constricted and measures only 12 mm. across. From this point the upper part forms a fan-like expansion, which measures 25*5 mm. from front to back. The greatest length of the ilium is 34 mm., and the least, measuring from the surface for articulation with the ischium to the anterior part of the crest, 22 mm. On the inner side of the ilium is a hollow depression just above the constricted portion, with a second slight depression behind it and separated from it by a low ridge. These depressions are for articulation with the two sacral ribs. The ischium is a flat semicircular bone not unlike the flat bone in Procolophon or Stereosternum. Though the acetabular portion is not displayed in Hoivesia, it is probably of - much larger size than in these other genera. It seems probable that the ischium sloped downwards and inwards at an angle of about 45°. The whole margin of the bone has manifestly been bordered by cartilage except the margin which is directed upwards. The lower margin for about 17 mm. is fairly straight, and forms, with the bone of the opposite side, a symphysis with probably comparatively little cartilage between. Anteriorly there is another fairly straight margin of 10 mm., which served as an articulation with the pubis, probably again with but little cartilage between the bones. Between the two ischia and the two pubes there is left a lozenge-shaped gap, like the anterior fontanelle in the head of a babe. This may have formed an obturator foramen, but I am of opinion that it was completely covered by cartilage. The pubis, though of the plate-like type, does not resemble at all closely the flat pubes of Procolophon, Stereosternum, or Palceohatteria. This is owing to the fact of the anterior third of the bone being bent rather abruptly down so as to form an angle of about 75° with the posterior part. The deflected portion has its outer and inferior end terminated by a thick margin, which seems |