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Show 1897.J MYOLOGY OF THE TERRESTRIAL CARNIVORA. 405 (53, 54, 55) and P. cancrivorus (57). In Nasua (60) it is figured by Cuvier and Laurillard, and, in all these animals, seems to end in the sheaths of the tendons. In Cercoleptes (61, 62) it forms the flexor perforatus of the little finger. In the Mustelidae it seems to be usually absent, or at all events very feebly marked; the only record we have of it in this family is in Mustela putorius. Palmaris brevis.-The palmaris brevis is apparently never present in Carnivora. Thenar Muscles.-This group consists of the abductor, flexor brevis, and opponens of human anatomy. Among the Felidae the only record we have is of the Cat (6), in which the abductor rises from the trapezium and annular ligament; the usual double-headed flexor brevis is present, and the opponens very small. From our experience of the rest of the muscles of the Felidae we presume that the other animals of the family closely resemble the Cat in their thenar muscles. In the Viverridae, we found a weak abductor and a well-marked flexor brevis in Cryptoprocta (10). In Viverra civetta (12) and Vlverrlcula malaccensis (15) the same muscles were found, though Devis (X.) describes an opponens in addition in Viverra civetta (14). In Paradoxurus typus (19, 20) and Herpestes griseus (24) the abductor and flexor brevis alone were found. In Proteles and the Hyaenidae there were no thumb-muscles. Among the Canidae we only found two muscles of the thumb in Canis familiaris (31), one going to the inner, the other to the outer sesamoid bone (see fig. 11, p. 406). It is difficult to determine whether these should be looked upon as two heads of a flexor brevis or as an abductor and adductor. The muscles were small and the nerve-supply somewhat difficult to be quite certain of, but we are of opinion that the radial muscle was supplied by the median, and the ulnar by the ulnar nerve. W e are further led to regard the latter muscle as an adductor pollicis by the fact that Cunningham (XLVI.) describes an adductor in the Dingo. The radial of the two muscles rises from the trapezium and is therefore probably an abductor, so that in the Dog a slender abductor pollicis is present, but no opponens or flexor brevis. Among the Ursidae, Kelley (XXIV.) only mentions a flexor brevis pollicis in Ursus marltlmus (45). Meckel (XXXIX.) describes the thenar muscles as very strong in U.arctos (47), the abductor in his specimen had two origins, from the trapezium and base of the first metacarpal; there was in addition a flexor brevis. In U. americanus (49) there were also abductor, flexor brevis, and opponens. Among the Procyonidae, P. lotor (53, 56) has an abductor and flexor brevis, while P. cancrivorus (57) has a small opponens besides. Cercoleptes (61, 62) has an abductor, flexor brevis, and small opponens. Among the Mustelidae, Alix (XXX.) describes a superficial and deep abductor pollicis in M. putorius (65); probably these correspond to our abductor and flexor brevis. In M. foina (66) the same two muscles exist, as they do also in Ictonyx (69, 70) and Lutra vulgaris (74). In Lutra cinerea (78) a small opponens was found bjr Macalister. |