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in the sauria a varying number of ribs comes into contact with 
the prosternum, neifher is it diminished by the fact that in the 
anura firmisternia the sternum becomes secundarily connected with 
the shoulder girdle. In this, as well as in the lately formed costal 
xiphisternum of the sauria one has to see adjustments to the further 
development of the anterior extremity as organ of locomotion and 
of support, a fact which is connected with the transition to landlife. 
| am unable to find, aided by the study of the literature relating 
to this, farther points of connection in crocodilia, aves and mammalia 
for the thesis developed in the preceding words. 
RECAPITULATION. 
1. The prosternum of the sauria is autochthonic and formed 
pairedly. A varying number of ribs becomes secundarily connected 
with the prosternum. 
2. The xiphisternium of the sauria is costal and is also formed 
pairedly. To its formation cooperate those ribs that follow after those 
fixed to the prosternum. 
3. The prosternum of the sauria is homologous with the sternum 
of the amphibians. Phylogenetically and ontogenetically it is older 
than the costal xiphisternum, developing in the sauria. 
