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Show 1889.] ANATOMY OF RHINOCEROS SUMATRENSIS. 17 Rhinoceros. Flex. obi. met. ... Origin by one head from flexor condyle, by a 2nd head partly from olecranon and partly from humerus. Ins. (1) by a tendon upon pisiform ; (2) by fleshy fibres upon radial side of carpus. Flex. int. met. ... Origin from flexor condyle. Ins. proximal end of radial metacarpal. Flex, perforatus... Origin from flexor condyle. Ins. bases of 2nd phalanx of all 3 digits. Flexor profundus. Origin from flexor condyle. Ins. bases of last phalanx of each digit. Palmaris longus (?) Present. Ext. met. Origin. Extensor condyle and radius. Ins. carpal end of middle metacarpal. Horse. Origin. B y two heads as in Ehinoceros. 2nd head arises only from olecranon. Insertion only on to pisiform. The same. The same, allowing for absence of phalanges of 2nd and 4th digits. Origin :-(1) From flexor condyle ; (2) olecranon ; (3) posterior surface of radius. Absent. Origin only from humerus. Rhinoceros. Extensor met Ext. comm. digit. Ext. lat. digit. .. Tapir. Origin only from humerus. Origin:-(1) Outer condyle ; (2) head of radius; (3) from middle of ulna. Origin from extensor condyle and from ulna and radius. Insertion, oute* digits 3 and 4. It will be seen from the above tabular comparison of some of the muscles of the Rhinoceros with the corresponding muscles of the Horse that there are some differences, particularly in the extensors. W e shall now compare the myology of Rhinoceros with that of Hyrax; our comparison is not based upon a dissection of Hyrax, but upon the detailed account of the muscular anatomy of that animal by Messrs. Murie and Mivart1. The extensor muscles of the manus in Rhinoceros are, as in the Horse, only four in number; the corresponding muscles in Hyrax appear to be as follows:- Rhinoceros, Horse. Extensor communis digitorum. Extensor lateralis digitorum. Extensor obliquus metacarpi. Extensor metacarpi. Hyrax. Extensor communis digitorum. Extensor minimi digiti. Extensor ossis metacarpi pollicis. | Extensor carpi longior. \ Extensor carpi brevior. 1 P. Z. S. 1865, p. 329. PROC. ZOOL. Soc-1889, No. II. |