| OCR Text |
Show 326 MESSRS. B. C A. WINDLE AND F. G. PARSONS ON [Mar. 7, In our specimens (1, 7) Ave found a feeble pectoralis minor rising from the second costal cartilage and passing to the fascia over the shoulder; Avhile the abdominal pectoral (pectoralis quartus) Avas present and closely blended Avith the abdomino-humeral part of the panniculus. Cuvier and Laurillard (6) show in their figure an absence of pectoralis quartus, thus agreeing AAith Macalister and Mackintosh, but they represent a fairly Avell-marked pectoralis minor. In Cholcepus a special bundle corresponding in origin to the superficial gladiolar fibres Avas inserted into the inner border of the flexor surface of the forearm. In Myrmecophaga (13) the superficial and deep manubrial fibres Avere fused and the superficial and deep gladiolar Avere distinct. There Avas no pectoralis minor. In Tamandua (14) and Cyclothurus (17, 18) the superficial manubrial and gladiolar fibres Avere fused. In Dasypus (22, 24) the same condition obtains, but the place of the deep gladiolar fibres is taken by the large part of the latissimus dorsi Avhich passes across the floor of the axilla and is inserted with the pectorals. In Tatusia (25) claAicular, sternal, and abdominal bundles are present, and the same description applies to Chlamydophorus (27). In Manis (29, 30, 32) the superficial manubrial bundle is Avell marked, and, although narrow at its origin, spreads out to be inserted from the lower end of the deltoid tubercle to the internal condyle. In one specimen (30) it is noted that these manubrial fibres are twisted upon themselves in such a way that those rising most deeply were most superficial at their insertion. In Oryeteropus, Macalister (I.), Humphry (IX.), and Galton (VIII.) all agree that a pectoralis minor is present. The pectoralis quartus (37) is also Avell marked. Subclavius.-This muscle iu the Edentates varies a good deal and is of considerable interest. In the Bradypodidce it is present and is inserted not only into the clavicle, but into the coracoid process and acromion. This was the case in six specimens of this animal (2, 3, 4, 5, 6, 7) and in tAAO of Cholcepus (10 and a specimen of Galton's). In the Myrmecophagidce the muscle is absent not only in Myrmecophaga (13) and Tamandua (14 aud X. p. 528), AA'hich have only rudimentary clavicles, but also in Cyclothurus (17, 18, 20, 21), in Avhich this bone is Avell developed. In the Dasypodidce the muscle is ahvays large and inserted chiefly into the acromion process and the fascia over the supraspiuatus. This is true of Dasypus (22, 23), Tatusia (25), and Chlamydophorus (27, 28). In the Manidce the muscle is wanting (29, 31, 32, 33, 34). In the Orycteropodidce the subclavius is present (35, 36), but, as in most Edentates, is inserted more into the acromion and fascia over the supraspinatus than into the clavicle. This arrangement is clearly an approach to the sterno-scapularis muscle so constantly fouud amongst hystricomorphine rodents. Deltoid.-The usual three parts of the deltoid are present in Edentates, and, as a rule, are inserted very close together into the deltoid ridge. Speaking generally, the usual mammalian rule is borne out, that clavicular fibres are inserted lowest and pass |
