VII.] 



MONO TREMA TA . 



The T-shaped bone, interclavicle or episternum (ic) in front 

 of the presternum, which connects it with the clavicle 

 and is often completely fused with it, appears to have 



sr 



IT 



FIG. 44. Sternum and adjacent parts of the skeleton of a young Ornithorhynchus 

 (p. anatiniis). c clavicle ; ic interclavicle ; po pro-osteon (a part of the true 

 sternum) ; ps presternum ; ms mesosternum ; jrsternal ribs ; ir intermediate ribs ; 

 vr vertebral ribs. 



no homologue among the other Mammalia, and belongs 

 more properly to the shoulder-girdle than to the sternal 

 apparatus. 



