REPORT ON THE MARSTJPIALIA. 89 



great interest therefore to find that the transformed muscles in some cases assume their 

 original condition. So far as I am aware no author has hitherto noticed these 

 ligamentous bands in the foot of the Armadillo. 



It is very unfortunate that Dr. Murie, 1 in his memoir upon the three-banded Arma- 

 dillo, owing to a mishap which befell the feet, was able to give so little information upon 

 the intrinsic muscles. He merely states that he was able to make out " strong interossei 

 and other flexores breves. They were fewer in number than those specified by Galton in 

 Dasypus." 



In Cuvier and Laurillard's plates of the six-banded Armadillo the intrinsic muscles 

 of the foot are not figured. 



In the highly interesting memoir upon the limbs of the Orycteropus capensis by Mr. 

 J. C. Galton 2 a series of fibrous bands are described in the foot which apparently represent 

 missing elements of the intrinsic group of muscles. He describes each as being " a 

 strong ligament which passes, forked at both extremities into a resemblance to an X, from 

 the plantar aspect of the base of the metatarsal to the sesamoids, at the base of the 

 proximal phalanx of each digit." They are confined to the three middle digits, and a 

 reference to the beautiful figure (pi. xlvi. fig. 3) which accompanies this memoir, renders 

 it apparent that they are transformed flexores breves. A fleshy short flexor for each of 

 the remaining digits (viz., the minimus and hallux) is also present. Fibrous bands of 

 a somewhat similar nature are bkewise found in the manus of the same animal, and Mr. 

 Galton calls them the " metacarpal ligaments." 



Professor Humphry 3 in his paper upon the myology of the same animal makes no 

 mention of these ligamentous slips. 



Bradypus tridactylus (PL IX. figs. 2, 3, 4). 



The remarkable hook-like character of the pes of the three-toed Sloth naturally 

 suggests a corresponding peculiarity in the arrangement of the intrinsic pedal muscles. 

 This we find to be the case. In this foot the index, medius, and annularis are alone 

 fully developed. These are pressed tightly together, and enveloped by a common integu- 

 mental covering, which reaches as far forward as the bases of the enormous claws. The 

 digits possess therefore almost no power of independent movement. Further, the proximal 

 phalanges of these toes are shortened to such an extent that they are merely represented 

 by three square osseous nodules of little more than a quarter of an inch in length, which at 

 an early age coalesce with the heads of the metatarsals, so as to render any movement at 

 the metatarso-phalangeal joints impossible. The metatarsus is flanked on each side by a 

 rudimentary metatarsal bone which supports no phalanges. These are rudiments of the 

 hallux and minimus. 



1 The Three-banded Armadillo, Trans. Linnean Society, vol. xxx. 



2 The Myology of the Upper and Lower Extremities of Orycteropus capensis, Linnean Transactions, vol. xxvi. p. 567. 



3 On the Myology of Orycteropus capensis and Phoca communis, Jour. Anat. and Phys., vol. ii. pp. 305 and 317. 



(ZOOL. CHALL. EXP. — PART XVI. — 1882). Q 12 



