40 ME. E. LYDEKKEE ON A CHELONIAN SCAPFLA. 



be more precisely termed, scapulo-precoracoid), partly concealed by 

 the matrix. The exact transverse diameter of the " neck " of that 

 scapula cannot be preciselj- determined, but it was evidently very 

 considerably less than in the present specimen, where it is upwards 

 of 6*7 inches. 



The especial interest of the present specimen is that it is more 

 like the scapula of Chelone than that of Dermoclielys, this being 

 especially shown by the sharpness of its ridges, notably the one at 

 the junction of the inferior border of the precoracoid with the neck, 

 and the long and triangular form of the facet for the articulation of 

 the coracoid. Indeed, if we had no evidence of the existence of 

 gigantic Dermocliehjidce in the London Clay, I should have been 

 disposed to refer the specimen to a member of the CJielonidce, by 

 the side of which the Chelone Hoffrnanni of Maastricht would be 

 a dwarf. 



Although too much stress should not be laid on the resemblance 

 of this bone to the scapula of the CJielonidce, yet it to a certain extent 

 supports the very strong evidence lately brought over by Dr. Baur * 

 as to the intimate affinity between the Dermoclielyidce and Chelonidce; 

 and I may take this opportunity of stating my belief that the writer 

 here mentioned has practically proved his view that the so-called 

 Athecata are nothing more than a specialized offshoot from the earlier 

 CJielonidce. In provisionally following the opinion of writers who 

 adopted an opposite view, I always felt it to be a great difficulty how 

 the resemblance between the limb-bones of the Dermocliehjidce and 

 the CJielonidcessi^^ to be explained if they had no direct affinity with 

 one another. 



I am glad to say, in conclusion, that Mr. Shrubsole has signified 

 his intention of presenting the specimen under consideration to the 

 National Collection. 



^ ' American Naturalist,' 1890, pp. 530 et seq. 



