Ichtliyosauria and Sauropterygia. 



237 



hum 



Cor. 



FIG. 1. Reduced copy of Sir E. Home's restoration of the pectoral arch of Ichthyo- 

 saurus ('Phil. Trans.,' 1818, PI. 2, fig. 1). CZ., clavicle; So., scapula; Int., 

 interclavicle ; Cor., coracoid. (This lettering indicates the identic pieces in 

 all the figures illustrating this paper.) The shading in the vacuity in front 

 of the coracoid has been added to show the position of the precoracoid (Seeley) . 



The unnatural proportions of the several bones shown in his recon- 

 struction (fig. 1, PI. 2, Phil. Trans.,' Part I, 1818), place it beyond 

 doubt that he derived his ideas from the dissociated bones of more 

 than one individual, and also that he had not at that time seen in a 

 single skeleton all the component elements of this arch in their 

 normal, or in but slightly disordered relation. 



Cuvier treats of the scapula very briefly ; he says,* " L'omoplate, 

 d, est aussi un peu dilatee en eventail vers 1'endroit ou elle s'unit au 

 coracoidien ; elle se retrecit, en se courbant, pour remonter vers le dos, 

 et elle a a son bord anterieur une preeminence pour donner appui a 

 I'extremite de la clavicule."f 



Although he added more than any other writer to the exact know- 

 ledge of the osteology of Ichthyosaurus (and Plesiosaurus), and this 

 chiefly from the study of specimens acquired by him in London for 

 the Paris Museum, it is noteworthy that he did not state his own 

 views on the shoulder girdle other than in very general terms ; nor 

 did he embody them in a "reconstruction"; but he copied (with 

 proper acknowledgment) the figure of this girdle in Sir E. Home's 

 " plate " ; at the same time he also reproduced the restoration given 

 by Conybeare, of the same skeletal part.J 



Now, Sir E. Home's and the Rev. W. D. Conybeare's reconstruc- 



* Cuvier, GK, ' Ossemens Fossiles.' Edit. 3. Tome 5, Partie 2, p. 47Q, 1825. 

 f Cuvier, Q-., ' Ossemens Fossiles,' loc. cit. 



j Conybeare, W. D. (and De la Beche), A New Fossil Animal, ' Geol. Soc. 

 Trans.,' p. 557, vol. 5, 1821, and Fig. 7, vol. 1, Part 2, 2nd Series. 



