268 PROCEEDINGS OF THE ACADEMY OF 



a. Characters exclusively shared with all Ungulates. 



None. 



h. Cliaracters exclusivelj- shared with all Pachj'derm Ungulates ; 

 that is, with the Suiform Artiodactyle Ungulates, the Perissodac- 

 tjle Ungulates, and the Proboscideans. 



None. 



c. Characters exclusively shared with all the Suiform Artiodac- 

 tyle Ungulates. 



None. 



d. Characters exclusively shared with all the Perissodactyle 

 Ungulates. 



None. 



e. Characters exclusively shared with all the Proboscideans. 

 None. 



Thus does it appear that in the whole argument, no characters 

 have been adduced which are common to all the Sireuians and the 

 Ungulates, or even to them and any of the major subdivisions of 

 the latter group. It is true that it is especially stated that the 

 Manatee agrees with the Pachyderms and differs from the Ceta- 

 ceans in the articulation of the ribs with the vertebrae, the form 

 of the scapula, the position of the occipital condyles, and the union 

 above of the parietal bones, and the inference might be justifiable 

 from the context that the characters specified were confined to, as 

 well as common to, the two groups, but such is not the case, for 

 all the characters in question are shared with quadruped mammals 

 generall}'. Being thus general, the characters are not decisive of 

 immediate relation and must be excluded as common property. 



It remains to examine into the taxonomic value of the other 

 characters enumerated, which are now reduced to types of no more 

 than family, and sometimes of inferior value. 



/. The Manatee is said to resemble the Hippopotamxis in the 

 'orbits almost entirely encircled with bone," and in the lower jaw 

 that is, " in its curved form, descending angle, and symphysis." 



As to the encircled orbits, the nearest allies to the Manatee 

 have them open behind, and the nearest ally of the Hippopotamus 

 {CIiu>7-o])sis, belonging to the same family and ver}' nearly related) 

 has them also open behind ; therefore, the slight taxonomic value 

 of the character becomes at once evident. 



As to the similarit}' of the lower jaw, the writer is unable to 

 perceive it, and the related forms of Sirenians and Hippopota- 



