. A manual of zoology for the use of students : with a general introduction on the principles of zoology . Zoology. GENERAL CHARACTERS OF THE VERTEBRATA. 3SJ series of bones which also correspond to one another in general structure. The fore-limbs,-often called the "pectoral" limbs, are united with the trunk by means of a bony arch, which is called the " pectoral'' or " scapiUar " arch ; whilst the hind- limbs are similarly connected with the trunk by means of the " pelvic ; In giving a general description of the parts which compose the limbs and their s
. A manual of zoology for the use of students : with a general introduction on the principles of zoology . Zoology. GENERAL CHARACTERS OF THE VERTEBRATA. 3SJ series of bones which also correspond to one another in general structure. The fore-limbs,-often called the "pectoral" limbs, are united with the trunk by means of a bony arch, which is called the " pectoral'' or " scapiUar " arch ; whilst the hind- limbs are similarly connected with the trunk by means of the " pelvic ; In giving a general description of the parts which compose the limbs and their supporting arches, it will be best to take the case of a Mammal, and the departures from this type will then be readily recognised. The pectoral or scapular arch consists usually of three bones, the "scapula" or shoulder-blade, the "coracoid," and the "clavicle" or collar-bone; but in the great majority of the Mammals, the coracoid is anchylosed with the scap- ula, of which it forms a mere process. The scapulaorshoulder-blade(fig. 127, j) is usually placed outside the ribs, and it forms, either alone or in conjunction with the other bones of the shoulder- girdle, the cavity with which the upper arm is articulated. The coracoid, though rarely existing as a distinct bone in .the. Mammals, plays a very important part in other Vertebrates, as we shall see hereafter. The clavicles are often wanting, or rudimentary, and they are the least essential elements of the scapular arch. The fore-limb proper consists, firstly, of a single bone which forms the upper arm, and which is known as the humerus [h). This arti- culates above with-the shoulder-girdle, and is followed below by the fore-arm, which consists of two bones, called the radius and ulna. Of these the radius is chiefly concerned with carrying the hand. The radius and ulna are fol- lowed by the bones of the wMSt, which are usually composed of Several bones, and constitute what is called the carpus (d)
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