| OCR Text |
Show 3 1 4 MR. R. H. BURNE ON THE [Apr. 18, in transverse diameter x 26 mm. in depth. Its hinder paits aie encased in a thick cartilaginous sclerotic, which thins out anteriorly where it meets the circlet of sclerotic bones. The latter resemble those of Ghelone in form, number, size, an arrrangement, but are stouter. Dermochelys coriacea, lids of the left eye seen from within. l.I. lower lid, I.p.m. levator palpebrae muscle, n. nictitating membrane, n.m. nictitator muscle. The outer parts of the sclerotic cartilage are hyaline, but towards the inner surface it gets more and more fibrous, the inner parts consisting of fibrous tissue interspersed with small and scattered centres of cartilage formation. The lens, like that of Ghelone, is relatively very small; it measures 7 mm. in the antero-posterior and 7‘5 mm. in its transverse diameter. The general anatomy of the alimentary canal has been accurately described by Rathke *, and more recently by Vaillantf. The following additions may be made to their accounts of these organs. •• The Oesophagus. (R. 0. S. Museum, Physiol. Series 461 B, 0, & D.) The horn-capped processes that beset the inner surface of the oesophagus are of all sizes. The larger ones average about 4 cm. in length, and, except in the pharyngeal region, are set so close * Rathke : " Uebcr die Luftrohre, die Speiserohre und den Magen der Sphargis coriacea," Arch. f. Anat. u. Physiol. 1846, p. 292. f Vaillant: " Remarques sur l 'appareil digestif et le mode d'alimentation de la Tortue luth," Comptes Rendus Ac. Sci. t. cxxiii. 1896, p. 654. Text-fig. 68. T h e A l im e n t a r y S y s t em . |
