AX ATOMY Of THE 



moreover, this coracoid is long enough to reach the breast bone, or sternum. The breast bone in the 

 Mammalia hitherto noticed consists of an expanded part at its fore end (in the usual position of 

 quadrupeds), or at its top in man, called the manubrium, and of some smaller pieces, which form the 

 front bone of the chest and reach to the belly, having ribs attached to them on each side. This is 

 the state of things in the Monotremes ; and the coracoids are attached to the manubrium, one on each 



IlVCK-BILLEl) PLATYPUS. 



side. In other Mammalia it is the collar bone which is jointed there. In addition te these breast 

 bones in the Monotremes, there are other bones in front, or between the neck and the top of the 

 manubrium. Firstly, there is a bone in the shape of a T : the lower point is on the breast bone, and 

 the cross-bar supports a collar bone on each side, which reaches outwards to the blade bone. 

 xxmdly, there is a bone 011 each side iu front of the coracoid, reaching forwards towards the neck. 

 This is called the epicoracoid. Some of these bones, now noticed for the first time, are more or less 

 common to birds, reptiles, and amphibians. 



There are some other anatomical points which ally the Monotremes to the reptiles. For instance 



the peg on the second, or axis vertebra of the neck, is not fixed to the bone by true bony matter, and 



the ribs which exist in the neck in the Monotremes are separate from the vertebra until late 



