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Show 194 DR. J. MURIE ON SAIGA TARTARICA. [June 9, hyoid has the usual attachments, but is very broad, and obliquely directed inwards and downwards or backwards. The thyro-hyoid is a remarkably long, broad, and thin sheet of muscular fibres: origin, sides of thyroid alae, exterior to the salient protuberance ; insertion, the whole of the basihyal and tbe thyrohyal cartilaginous rods. A broad portion of the median constrictor passes on to the thyroid ala beneath it. The stylo-hyoid, fleshy and strong, pierced by the median tendon of the digastric muscle, is inserted broadly into the basihyal. I may note also the presence of a large triangular fleshy muscle, the so-called hyo-keratic of some authors (Hk). The crico-thyroid is notable by the obliquity of its fleshy fibres. These meet in the median line, are attached to the upper border of the cricoid in front, but laterally cover it; ascending backwards, the fibres are inserted into the cricoid margin of the thyroid ala. The posterior crico-arytenoidei (P. c. a) are large but thin, and fit the shallow concavity of the cricoid shield. Owing to the oblique downward position assumed by the anterior cricoid ring, only short narrow wedged-shaped fasciculi of muscle represent the lateral crico-arytenoidei (L. c. a). Each arytenoideus muscle (Ar) is fairly developed, and, as usual, fills the post-concavity of the arytenoid cartilage. The thyro-arytenoidei (Th. a & Th. a. I & 2) are great soft muscular bands imbedded amongst and partially interwoven with fatty tissue. They take origin within the cavity of the thyroid prominence, and, proceeding backwards and upwards, partly covered by the cricoid and thyroid alae, are inserted into the root and outer margin of the arytenoid cartilage. The bones composing the complex hyoid arcb are each relatively long; but there does not seem to be present such a very elongate fibro-cartilaginous styloid cord as is figured by Pallas in the male Antilope gutturosa. In the Saiga, as in it and the Sheep, the basi- (B h) and thyro-hyals (T h) thoroughly interblend together and constitute a high arch, from tbe summit of which three short blunt processes spring. The middle one, the strongest and most projecting, is the rostrum of the basihyal; the outer ones, or wing expansions of the bone, give lateral breadth rather than branch forwards. From these the styloform thyro-hyals retrograde. The basihyal is just under 1 inch broad, and each thyro-hyal lh_ inch long. The latter were cartilaginous, the former semiossified in the Society's male specimen. The cerato-hyals (C h) have a free articular surface at eacb end. The epihyals nearly correspond, though, unfortunately, not defined or lettered in A, fig. 11. They each are less than an inch long, their ends swollen and body laterally compressed. The stylo-hyal (S h) is fully 3 inches in length, the body slender, but the cranial end expanded into a flat somewhat rhomboidal figure. The upper spur terminates in a small tympanic bulb ; the lower spur broadly descends, and, with concave antero-posterior margins, bends forwards in a spine. Comparing the hyoid of Saiga with tbe Sheep's, it is altogether more delicate, and each bone longer. The spurs of the cranial end |
