Page:Popular Science Monthly Volume 17.djvu/791

Rh root for worms in the mud, or catch insects and small animals. They have a peculiar, fishy smell, and are eaten by the natives; but this is no sign that they are good, for the natives have no taste. They belong to the lowest group of the mammalia, the Monotremata, which includes the two genera Ornithorhynchus and Echidna, both these genera exhibit an arrangement of the breast and shoulder-bones which is in a certain degree similar to that of the lizard and the extinct ichthyosaurus. In all the higher mammalia, the humerus is attached to the shoulder in a hollow of the scapula or shoulder-blade; in the ornithorhynchus, the hollow in which the ball of the humerus rests contains a bone connected with the shoulder-blade called the coracoid bone. The breast-bone in the mammalia consists of a broad

—The shoulder-and breast-bones and ribs of the Echidna, a, T-shaped intermediate bone; b, manubrium; c, the sword-shaped end of the breast-bone; d, cartilaginous ribs; e, key-bone; f, the coracoid; g, the epicoracoid bone.

bone placed in front in quadrupeds, above the others in man, called the manubrium, and several smaller bones, which reach down to the belly, and have ribs on both sides; while in the other mammalia the manubrium is in contact with the neck-bone, in the ornithorhynchus the two coracoid bones are in contact with the manubrium. Some other bones are found on the breast and neck which are wanting in the other mammalia: first, a T-shaped bone which joins the breast-bone from below, and the cross of which bears at each end a neck-bone that reaches to the shoulder-blade; also, on each side in front of the coracoid bone, a so-called epicoracoid bone reaching to the neck. Some