442 ME. ST. GEORGE MIVART ON THE 



The postaxial margin is sharp, and becomes more prominent at the angle, causing 

 this part of the margin to be convex. 



At about the dorsal end of the distal third of the postaxial margin of the rib a large 

 lamelliform uncinate process is thrown out. It stands out at its origin nearly at right 

 angles to the course of the rib, and then turns sharply dorsad and tapers to a point, 

 running nearly parallel to the course of the rib ; the uncinate process is thus bent at 

 right angles. 



The Fifth Rib. 



This rib (fig. 75, v & v') which is attached dorsally to the twenty-second vertebra, 

 closely resembles the fourth : it is, however, larger ; and its distal part is more slender, 

 expanding, nevertheless, at the distal end to form a concave surface for junction with 

 the third sternal rib (fig. 1, v). 



Both the capitulum and tuberculum are longer and diverge at an angle of about 75°, 

 having a large pneumatic foramen (fig. 75, v', /) at the vertebral margin, where they 

 bifui'cate. 



The length of the capitulum, as compared with that of the tuberculum, has also 

 somewhat increased. 



The shaft of the rib is more bent on the head and tubercle, and has a rather more 

 decided " angle ;" but its margins are in the main similar to those of the third rib. 



The uncinate process {u) is placed more proximally, springing from nearer the middle 

 of the length of the shaft of the rib ; it extends out rather less, and its recurved portion 

 is more slender. 



The preaxial margin of the shaft is continued into that of the tuberculum by a ridge 

 (fig. 75, v', near/") passing outside the root of the capitulum, i.e. preaxially to that root. 



The Sixth Bib. 



This rib (fig. 75, vi) is attached to the twenty-third vertebra, and very closely 

 resembles the fifth, which it about equals in length ; its distal half, however, is more 

 slender and more rounded, though its distal end may, on the contrary be more expanded. 

 It articulates distally with the fourth sternal rib (fig. 1, vi). 



The pneumatic foramen is larger ; and the capitulum and tuberculum diverge at an 

 angle of about 80°. 



The proximal part of the shaft of the rib is rather more bent. 



The uncinate process {u) springs from the dorsal margin, at about the middle point 

 between the distal end of the rib and the root of the tuberculum. It is very much 

 smaller, and, though rather broader at its root, much blunter, and may be not half the 

 length of the recurved part of that of the fifth rib. 



The articular surface for the diapophysis is rather larger and more concave. 



The ridge passing outside the root of the capitulum is more marked than in the 

 fifth rib. 



