164 



Transactions . — Zoology. 



marked in all the ribs following the 2nd, and the curvature 

 is more gentle and regular. The upper region, instead of 

 being horizontal, is inclined downwards, and this general 

 form is retained by the rest ; but the convexity of the curve 

 decreases, so that the ribs, as traced backwards, tend to 

 become straighter. 



In the 7th and following ribs the capitulum ceases to 

 articulate with any vertebra ; it is bluntly pointed, and pro- 

 bably connected by ligament to the column. 



The 13th rib has been described. 



There is no important difference between the ribs of the 

 right and left sides. I add a table of measurements. The 

 length of the rib is measured in a straight line from the inner 

 margin of its articular extremity to the inner margin of the 

 distal extremity. The "curvature" is really the distance of 

 the most remote point on the inner margin from the line 

 joining the two extremities of the ribs. 



The sternum, has not, as far as I am aware, received a 

 detailed description by any previous author, for it was onlv 

 partially recovered for Wall's specimen, and Von Haast 

 makes no mention of it. In the present specimen it and the 

 sternal ribs are complete. It consists of three sternebrae^ 

 the first and second formed of a single bone, the last of a pair 

 of small bones imbedded in cartilage. There are four pairs of 

 sternal ribs, measuring respectively 90 mm., 75 mm., 60 mm.,. 

 and 30 mm. 



The total length of sternum, including the cartilage at 

 each extremity, is 260 mm. ; the greatest breadth, measured 

 just behind the articulation of the first sternal rib, is 155 mm. - r 



Together with cartilage above and below. 



