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Show 32 DR. F. G. PARSONS ON THE [Jan. 1 5, The gastrocnemius is as Dobson describes it; there are no fabelhe in its heads of origin. The plantaris tendon passes under the tuber calcis and is continuous with the flexor brevis digitorum and plantar fascia in the sole. The popliteus lies, as in most mammals, behind the anterior tibial artery. The flexor fibularis resembles the flexor profundus digitorum in the fore limb in having its tendon ossified ; in both m y specimens there were two sesamoid bones, one at the ankle and another in the sole. The flexor tibialis is only imperfectly separated from the last muscle in the calf, and the two tendons fuse in the lower part of the leg. The abductor ossis metatarsi minimi digiti is feeble ; while the tibialis posticus, accessorius,and flexorcs breves agree \A it li Dobsou's description. There is only one lumbrical, the outermost, in one specimen ; in the other the two outer ones are present. Articulations. The joints of Chrysocldoris are in many respects those of a generalized mammal in spite of its extremely specialized fossorial habits. As I have in another place1 given a description of the joints of mammals, I shall not take up space by drawing attention to the details which this animal shares with other mammals, but shall only mention the points of special importance. The temporo-maxillary articulation is a perfect hinge, and the condyle is elongated transversely to fit into a socket bounded by a definite pre- and post-glenoid process. The meniscus is very thin and concave downward. The whole articulation is of the carnivorous type. The sterno-clavicular articulation consists of a short fibrocartilaginous band which connects the sternal end of the clavicle to the dorsal side of the anterior (cephalic) margin of the presternum. No ossific nodule was present in this band, nor could I make out any synovial cavity between it and the sternum. The presence or absence of a synovial cavity at the sternum seems to depend very much on the histological structure and consequent, rigidity of the connection between the bony clavicle and the sternum. In the Hedgehog, for example, there is a synovial cavity, but then the rod of connective tissue is much more densely chondrilied than it is in Chrysocldoris ; indeed, in the latter animal the connecting band between the two bones is so flexible that a synovial joint would be quite superfluous. The coraco clavicular ligaments are absent; the acromion is so long and projects so far forward that the clavicle is carried far Journ. Anat. vol. xxxiv. |