15 
respect the Siren dijffers very materially from 
the Proteus anguiims, if we can depend upon Dr. 
Schreibers’s account of that animal : for this natu- 
ralist says, the Proteus has no nostrils.’’ I cannot 
but suspect, that future observations will show us, 
that the Proteus has nostrils, though, perhaps, very 
small ones. If Dr. Schreibers’s observation be cor- 
rect, he has furnished us with a very good external 
mark of distinction, between the Carniolian and A- 
merican animals. But, indeed, we do not stand in 
need of this character to discriminate the Proteus an- 
guinus and the Siren from each other. 
It appears to me, that the nostrils of the Siren per- 
form a two-fold office. They admit both water and 
air. While the animal lies buried in the water, I 
have often observed small particles of mud, &c. car- 
ried, along with the water, into the nostrils. When 
he swims about very rapidly, at which time I have 
supposed that his brauchiae are not of much use to 
him, as respiratory organs, he frequently puts the 
upper and anterior part of his head out of the water, 
without, so far as I have observed, opening his mouth 
at all. At such times, if I do not greatly mistake, he 
breathes almost entirely through the medium of his 
nostrils. 
But notwithstanding it is my opinion, that the nos- 
trils of the Siren assist this animal in its respiratory 
function, I must not conceal, that the internal narcs 
are situated at a considerable distance from the rima 
or opening of the trachea ; and that I have not been 
able, in the animal preserved in spirits (for I have 
not had an opportunity of making this experiment 
