TTPO:sr HTPEEODAPEDOJST GOKDOKT. 



687 



yieasurements of the Shoulder-girdle and Fore Limb in millimetres. 



Interclavicle, length 



,, greatest width . . . . 



Clavicle 



Coracoid, length 



„ breadth 



Humerus, length 



width at proximal 



end 



„ at distal end. . 

 shaft in the middle. . 



11 



Hyperodapedo7i. 



Sphenodon. 



VKJ ( dUOUL ) 



Oi 



17 



3 



100 (about) 



20 



58 





42 



11 



130 



33 



62 



11 



? 



11 



20 



2-5 



id. 



9(1 



20 



4 



13 



4 



74 



25 



30 



5 



20 



5 





6-5 





9-5 



17 



11-0 





10-0 





6-0 



Radius, length 



„ width, proximal .... 



,, „ distal 



Ulna, length 



,, width, proximal 



,, ,, distal 



Metacarpals : — 



u 



ii. I 



iii- > 



iv- I 



v.J . 



The right half of the pelvis is exposed ; but the pelvic bones are 

 a good deal crushed, and it is difficult to arrive at an unquestionable 

 interpretation of the appearances they present. There is no doubt, 

 however, as to the position of the obturator foramen, bounded in front 

 by the pubis and behind by the ischium. The former bone (PI. XXVI. 

 fig. 12, pb) is transversely elongated, and somewhat narrow in the 

 middle ; it widens out at both ends. At the inner extremity it is flat 

 and thin, and presents a convex symphysial contour. At the outer 

 extremity it is developed forwards into a strong prepubic process 

 and backwards into a thick acetabular portion. The bone is there- 

 fore quite Lacertilian. The thick acetabular portion of the ischium 

 (Plate XXVI. fig. 12, is) is in connexion with that of the pubis, and 

 the concave obturator margin of the bone can be well made out. 

 The difficulty is to say how much of the mass of bone which lies 

 behind this point (oc, fig. 12) belongs to the ischium and how much to 

 the ilium, which seems to be crushed down upon the ischium. If, 

 as appears probable, the posterior contour of the ischium is indicated 

 by the curved depression (a a, fig. 12), the ventral half of the pelvis 

 will be quite like that of ordinary Lizards, and the rest of the bony 

 matter belongs to the ilium. On the other hand, the form of the 

 ischium in JRhynchosaurus rather leads to the supposition that the 

 ischium was expanded inwardly and prolonged further backward, so 

 as to be unlike that of Sphenodon. 



The chief bones of the right hind limb (Plate XXVI. fig. 12) are 



