334 MESSES. B. C. A. WINDLE AKD E, G. PARSONS ON [Mar. 7, 



tendon to the rudimentary pollex. Ori/cferojnis (35, 37) has 

 condylo-uhiar and central parts, also radial and ulnar. The 

 common tendon, which possesses no sesamoid, gives off four 

 tendons. 



Lumhricales. — Amongst the Brach/podidce, Bradj/jms (1, 2, 3) is 

 devoid of any of these muscles, but Cholcejms (9) has two, one for 

 each digit. In the Myrviecophagidce two specimens of Myrmecopliaga 

 (11, 12) had four muscles, whilst another (13) had only two. 

 Tamandua (14) had three, that for the index being absent, but in 

 another specimen (16) there were six. In Cyclotliurus two speci- 

 mens (18, 20) had two lumhricales, whilst another (17) had none 

 at all. Dasyjjiis (22, 23, 24) possessed none at all. In Ghlamy- 

 dophorus Hyrtl (28) failed to find any ; but in another specimen 

 (27) seven slender fleshy bundles are described as rising from the 

 sesamoid cartilage in the flexor tendon, which are inserted into 

 each side of the middle phalanges of all the digits except the 

 pollex. In Maiiis the number is very variable ; there were three 

 in (30), four in (32) and (34), and two in (33). In all the specimens 

 of Orycteropus of which we have records (35, 36, 37) there were 

 four. 



Pronator quadratus. — Amongst the Bradyjjodidce this muscle is 

 very small, both in Bradypus (1, 2, 3, 5) and Cholospus (8, 9, 10), 

 occupying in the former only one-eighth to one-sixth of the fore- 

 arm. Tlie Myrmecophagidce, viz. Myrmecopliaga (12, 13), Tamandua 

 (14), and Cyclotliurus (17, 18, 20), have the muscle extending over 

 the whole length of the interosseous space. In Myrmecophaga 

 (12), Pouchet notices that the lower tliird of the muscle corre- 

 sponds to the human pronator quadratus in being attached to the 

 surfaces of the radius and ulna, whilst the upper two-thirds is 

 attached only to the opposed margins of the bones. In the JDasy- 

 podiclce and Manidce the muscle is usually absent, this being the 

 case in Basypus (22, 23), CJilamydojihorus (28), and Manis (29, 30, 

 31, 32, 33,34). In. Tatusia (25, 26) it was extremely rudimentary, 

 and in one specimen of Clilamydopliorus (27) it was represented 

 by a feeble fibrous cord. In Orycteropus (35) it occupied the 

 whole length of the bones, as was the case in the Myrmecopliagidce, 

 though Humphry describes it as being small. 



Supinator longus. — This muscle is always present in the Brady- 

 podidw and is often double. Of four specimens of Bradypus, three 

 (2, 4, 5) had the muscle delaminated into a superficial and a deep 

 layer, both of which arose from the supracondylar ridge, the more 

 superficial being inserted lower down than its deeper fellow. In 

 the other three specimens (1, 3, 6) the muscle was single and rose 

 from the lower half of the humerus. In the last of these (6) 

 the supinator longus and pronator radii teres joined before their 

 insertion. The bilaminar condition of the supinator longus was 

 found in all three specimens of Choloepiis of which we have records 

 (8, 9, 10). In 9 the superficial layer was inserted into the fascia 

 over the wrist, the deep into the radius. In the other specimens 

 (8, 10) both parts were attached to the radius. In the Myrmeco- 



