[Illustration: FIG. 15.—Skeleton of Lion (_Felis leo_). _cd_, Caudal vertebræ; _cp_, carpus; _cr_, coracoid process of scapula, _cv_, cervical vertebræ; _d_, dorsal vertebræ; _fb_, fibula; _fm_, femur; _h_, humerus; _il_, ilium; _isch_, ischium; _l_, lumbar vertebræ; _m_, metatarsus; _mc_, metacarpus; _p_, patella; _pb_, pubis; _ph_, phalanges; _pv_, pelvis; _r_, radius; _s_, sacral vertebræ; _sc_, scapula; _sk_, skull; _tb_, tibia; _ts_, tarsus; _u_, ulna; _zy_, zygomatic arch.] _Anterior Limb._—The anterior limb is present and fully developed in all mammals, being composed of a shoulder girdle and three segments belonging to the limb proper; viz. the upper arm or brachium, the forearm or antebrachium, and the hand or manus. _Shoulder-girdle._—The _shoulder_ or _pectoral girdle_ in the large majority of mammals is in a rudimentary or rather modified condition, compared with that in which it exists in other vertebrates. In the Monotremata (_Ornithorhynchus_ and _Echidna_) alone is the ventral portion, or coracoid, complete and articulated with the sternum below, as in the Sauropsida; and in this group alone do we find an anterior ventral element, apparently corresponding with the pre-coracoid of the Anomodont reptiles, although generally known as the epi-coracoid. In all other mammals the coracoid, though ossified from a distinct centre, forms only a process, sometimes a scarcely distinct tubercle, projecting from the anterior border of the glenoid cavity of the scapula. The last-named cavity, which in the Monotremes is formed jointly by the scapula and coracoid, receives the head of the humerus, or arm-bone. The scapula is always well developed, and generally broad and flat (whence its vernacular name “blade bone”), with a ridge called the “spine” on its outer surface, which usually ends in a free curved process, the “acromion.” As the scapula affords attachment to many of the muscles which act upon the anterior limb, its form and the development of its processes are greatly modified according to the uses to which the member is put. Thus it is most reduced and simple in character in those animals whose limbs are mere organs of support, as the Ungulates; and most complex when the limbs are also used for grasping, climbing, or digging. The development or absence of the clavicle or “collar-bone,” an accessory bar which connects the sternum with the scapula and steadies the shoulder-joint, has a somewhat similar relation, though its complete absence in the Bears shows that this is not an invariable rule. A complete clavicle is found in Man and all the Primates, in Chiroptera, all Insectivora (except _Potamogale_), in many Rodents, in most Edentates, and in all Marsupials, except _Perameles_. More or less rudimentary clavicles (generally suspended freely in the muscles) are found in the Cat, Dog, and most Carnivora, _Myrmecophaga_, and some Rodents. Clavicles are altogether absent in most of the _Ursidæ_, all the