64 ^- J- Anderson, Measurement of ribs. 



In Cebus the lower expansion is continued up for 20 mm. more 

 or less in the anterior 9 ribs and the ribs are constricted above this. 



In one skeleton the expanded lower end is carried up but in the 

 posterior (lower) the vertebral halves are are very wide for 20 mm. 

 (From 8 — 11) and then become distinctly wider and keep their width 

 for a shirt distance and then diminish to the angles. Beyond which 

 point the radial breadths again increase. 



The lower end of the 11*^ is notched. The posterior borders in 

 the middle thirds are sharp. 



In Cercopithecus. Tangential diameter increased outside angles. 

 The rod like character is not present below. 



In Rapale Jacchus the upper halves of middle ribs are wide. 



Mydas rufimanus 65 mm. in depth. The ribs are wide from the 

 angle to the junction of the middle and lower thirds 6, 7, 8 and 9 

 widest. Breadth diijainishes below. Anterior margins of all except 

 the first three or four sharp, inner edge grooved. 



Ribs thickest near the middle or a little nearer the upper border. 



The ribs in man are well known. A an account of the diameters 

 and of the change in the different ribs as the are traced backwards 

 will be found in the English Journal of Anatomy for 1884. 



We then see that mammalian ribs may be expanded. 



1. Radially in their whole length. 



2. Tangentially in their whole length. 



3. Radially above and tangentially in below. 

 The varieties under these three heads are given. 



The normal number of ribs was not present in some cases. 



In some the ribs are so wide that the intercostal spaces are 

 entirely occluded. In others the great breadth of the ribs causes 

 the intercostal spaces to be gieatly diminished. And the intercostal 

 muscles are so fixed that overlapping is not interfered with by the 

 attachment of these muscles. 



