134 New Species of Siren. 



But nature, who groupes together her productions accord 

 ing to their real affinities, abhors this violence ; and whatever 

 we attempt to effect by our arrangements, will always prove 

 imperfect and absurd, in the same degree as we depart from 

 her simplicity. 



On the much-disputed question respecting the respiration' 

 of animals of this genus, I shall merely add to what I have 

 before said on the subject,* that it is impossible for the oper- 

 cula of their spiracles to perform the same functions as the 

 branchiae of fishes ; even in that species which has them so 

 finely fimbriated, inasmuch as they are covered with the 

 common skin. But allowing that the fringed appendages of 

 the Siren lacertina are necessary to respiration, or are a kind 

 of external gills, what shall we say of the two other species 

 that have these appendages undivided ? With regard to the 

 lungs, or air vessels as they have been called, I really cannot 

 see that they differ at all from the same organs in all animals 

 of a similar nature, even the more perfect. The Amphiuma, 

 likewise,has the same kind of lungs, and its spiracles are merely 

 opened and closed by the expansile and contractile power of 

 the surrounding parts. 



Future observations will do doubt make us better acquainted 

 with these anomalies to our systems, and we may probably in 

 time, increase the number of species of Siren. I have little 

 doubt from the fact of Africans giving a name to the Siren 

 striata, that some animal resembling it may be found in the 

 swampy regions of their country. 



PL I. fig. 1. Siren intermedia. Fig. 2. the opercula 

 magnified. 



* See Annals of the Lyceum, Vol. I. p. 54. I am happy to have an 

 opportunity in this place of acknowledging-, that I now consider the Lake 

 Chatnplain animal to be a perfect animal, and not a larva. 



