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Show 1881.] OF CERCOPITHECUS CALLITRICHUS. 817 C. callitrichus (Dobson). G. saBaus (Mivart). 1. Omo-hyoid present. 1. N o omo-hyoid. 2. Trapezius partially inserted into 2. Trapezius had no insertion into the clavicle. the clavicle. 3. Pectoralis major arose from al- 3. Pectoralis major without the cla most the whole length of the clavicle. vicular origin. 4. Pectoralis minor consisted of two 4. Pectoralis minor consisted of two very distinct portions, one of which very distinct portions, which were was inserted into the capsular ligament, together inserted into the capsular the otber into the edge of the bicipital ligament. groove. 5. Levator clavicula partially in- 5. Levator clavicula? not at all inserted into the clavicle. serted into the clavicle. 6. Extensor ossis metacarpi pollicis 6. Extensor ossis metacarpi pollicis had but a single tendon. gave rise to two tendons. 7. Extensor indicis gave off (in addi- 7. Extensor indicis gave off tendons tion to those for the second and third to the second and third digits only. digits)a tendon for the fourth digit also. 8. Lumbricales bad similar origins 8. Lumhricales had different origins in both feet. in both feet. 9. Plantar interossei inserted by 9. Plantar interossei inserted like pairs into the sides of the proximal the palmar interossei of the human extremities of the phalangeal bones. hand. Other less important differences might also be noted in the connections of other muscles as described; but these might be found between any two specimens of the same species. If Mr. Mivart's specimen really belonged to the same species as mine does, the muscular differences above noted are exceedingly remarkable. Since writing the above, I have been enabled, through the kindness of Mr. W . A. Forbes, Prosector to the Society, to dissect another specimen of this species, a young female which had lately died in the Society's Gardens. The general conformity in its muscular structure with that of the robust male above-described was remarkable, the slight differences observable being almost confined to the extremities. The omo-hyoid was even better developed, and was united, at about an inch from its insertion, with the outer margin of the sterno-hyoid; the trapeziush&d not only a clavicular insertion but occupied fully one third of that bone; although the levator clavicula arose by a single head from the atlas, it soon divided into two large muscles as above described. In the right forearm a remarkable individual peculiarity was found : the tendon of the extensor secundi internodii pollicis ended abruptly above the carpus by being inserted into the interosseous ligament, and the tendon for the pollex was derived from the extensor indicis, which, as in Mr. Mivart's specimen, sent a tendon to the third but none to the fourth digit. The small anomalous muscle described above as arising from the annular ligament near the insertion of the tendon of the flexor carpi radialis, and inserted into the terminal phalanx of the pollex was not found. In the foot the only differences noticeable were found in the short flexor tendon for the second digit, which was not connected by muscular fibres with the tendon of the flexor digitorum longus, and in the presence of a separate muscular slip which arose P R O C . Z O O L . Soc-1881, N o . LIII. 53 |