in Ichthyosauria^and Sauropterygia. 



245 



Cor. 



Pr. 



Fia. 7. Scapula, coracoid, and precoracoid of Dicynodon (sp.). Owen, * S. Afrie. 



Kept.,' PI. 69, fig. o. 



(fig. 9, PL 9, ' Phil. Trans.,' B, 1889). Its form differs notably from 

 that of Pareiasaurus in the great length of its sagittal bar, but the 

 clavicle and the scapula are not known. In Keirognathus cordylus 

 (figured by Professor H. G. Seeley, ' Phil. Trans.,' B, 1890, PI. 75), 

 the clavicles are represented by small discontinuous fragments 

 of doubtful interpretation. The bone, with much probability in- 

 terpreted as interclavicle, is imperfect ; its relation to the coracoids, 

 precoracoids, and sternum are unusual. The coracoids and precora- 

 coids are represented only by impressions in the matrix to which but 

 vestiges of bony tissue remain attached : and the scapula is also ex- 

 tremely imperfect. 



I submit, then, that our present knowledge of the Anomodont 

 shoulder girdle is too incomplete to serve for any other than a very 

 general comparison with that of Ichthyosaurus ; and I venture to 

 think that at present it is insufficient to warrant the conclusions of a 

 close agreement in their structural details. 



I pass on to the Plesiosaurian shoulder girdle. Since the quali- 

 fying prefix inter' in interclavicle, and epi- in episternum, primarily 

 denote a relation of position and not of genesis, it does not appear 

 to me a matter of great moment which of these names is employed,, 



