70 Royal Irish Academy. 



portion of the body corresponds with the sternum of the vertebrata ; 

 whereas in insects there is a complete inversion. This lower part 

 to which the limbs are attached does not correspond with the ster- 

 num but with the back. Then the internal viscera should be viewed 

 in this same relation ; they lie upon or are above the back, and are 

 truly Agastric not hypogastric. When furnished with wings, if 

 with two pair, the anterior proceed from the true thoracic arch, the 

 posterior from the pelvic. In the turtle the three arches are beauti- 

 fully seen ; the pro-thoracic in the jaw, then the thoracic, and finally 

 the meta-thoracic or pelvic. In this group, as in some of the neigh- 

 bouring ones, from the peculiar arrangement of the pelvic and other 

 bones, the heel is turned forwards and the toes backwards. In fishes 

 M. Geoffroy St. Hilaire attempted to establish an analogy between 

 the bones of the operculum and the ossicula of the ear. But this is 

 quite wrong : these bones are nothing more than a peculiar arrange- 

 ment of the thoracic arch and fore-arm, as may be seen in the osseous 

 arrangement, in its connexion with the respiratory function in the 

 gills. The Proteus when viewed in its compound character presents 

 no exception. Again, not a less common, though equally glaring 

 mistake is made with regard to the pectoral fin and the deeper 

 seated parts connected with it. Proceeding upon analogical consi- 

 derations, the bones have been designated the scapular, proscapular, 

 humerus, &c, whereas the true analogy of these parts is not with 

 the shoulder but with the pelvic limb. As the osseous system, cor- 

 rectly contemplated, demonstrates this, so do the soft parts, and 

 more especially the nerves, whether we look at the nerves of sensa- 

 tion or motion, or the portio dura of the 7 th. The pro thoracic arch, 

 as already stated, is found in the jaw, and here the analogy is as 

 conspicuous as elsewhere. On looking at the skeleton of the Lophius 

 there appeared to be a contradiction, for here we find something so like 

 a fin or hand, that it cannot fail to be taken for it ; but in seeking for 

 it in the recent specimen it is not to be found ; in truth it is so ru- 

 dimentary, that it never reaches, far less protrudes from, the skin. 

 These are merely a few hints upon a very extensive and interesting 

 subject, which the author would do well to illustrate in a more 

 systematic and satisfactory manner than was possible in a short 

 verbal communication. 



ROYAL IRISH ACADEMY. 



May 28, 1838. — Sir W. Hamilton, A.M., President, in the Chair. 

 Mr. Ball read a paper, by Wm. Thompson, V.P., Nat. Hist. So- 

 ciety of Belfast, " On the Irish Hare." (Lepus Hibernicus.) 



