AMPHIBIANS. 89 



The first of these, the " omosternum," is the key-stone of the Shoulder-girdle; the second, the 

 " inter-clavicle," is an azygous Shoulder-splint a dermal bone ; whilst the last is the key-stone 

 of the first pair of thoracic ribs, and often of the last cervical as well (where, however, the piers of the 

 arch are aborted). Following our author, we find him speaking of the true Sternum of the Frog 

 as a part, whilst the remainder, or manubrial portion, is supposed by him to be formed by what 

 I have called the "omosternum" in that animal: in the Reptile and Monotreme Duges makes 

 up the Sternum by adding the " inter clavicle :" we shall see that Rathke makes up the Reptilian 

 Sternum in a similar way. At page 67 the Blind-worm {Anguis fragilis) is introduced ; and 

 as I shall come to that very soon, I may remark upon his views at once. His figure (plate iii, 

 fig. 27) may be compared with mine (Plate -VIII, figs. 2 7). Small as is his figure, it can be 

 easily understood by reference to the large ones which I have given. 



Duges truly says that the episternal (omosternum) is absent, as in Toads, and that his 

 " acromial" (clavicle] is attached to the supra-scapula, whilst the huge epi-pra-coracoids are 

 described as "clavicles." The " praesternum," or manubrium, the only part of the Sternum 

 present in Anguis, is called, as is also the Sternum of Pipa, " xiphoid." In the latter the prae- 

 meso-, and xiphisternum are all contained virtually in one generalised piece, but in Anguis the 

 Sternum is only correlated to the Shoulder-girdle, and scarcely answers to the whole of the 

 Mammalian manubrium. His little figure gives the shape exactly, but the three apparent bony 

 centres are the " inter-clavicle" and the two endosteal patches which in reality belong to the 

 Sternum. The remainder of his remarks, which relate to the serial homologies of the Shoulder- 

 girdle and Pelvis, are excellent. 



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