244 Scientific Proceedings, Royal Dublin Society. 



Scapula. 



The measurements in the accompanying Table show tliat, although there 

 is a good deal of variation in L. variabilis, which appears to be principally 

 due to age (e.g. the young specimen No. 3283 R.G.S.), the scapula in this 

 species is considei'ably wider above than in L. europmis. In this respect the 

 scapulae of the nearly complete skeleton from Ightham agree with those of 

 the adult recent L. variabilis, although much larger. The increase of width 

 is due to the much greater backward extension of the post-scapular surface 

 in L. variabilis than in L. eicropceus. The form of the glenoid articulation 

 and of the notch separating it from the coracoid process is very variable. 

 In some of the fossils the notch is very wide ; in others, including the perfect 

 example measured, very narrow. The same variation is seen, however, in 

 the recent skeletons of L. variabilis and also in those of L. euro2xeus. 



