newly discovered genus of serpentiform fishes. 57 
observed, it appears to have lost all its muscular energy. Its 
entire form would indicate great swiftness of motion, which 
is doubtless effected by means of the same interesting sinuous 
inflections in the water, which excite our admiration in the 
class of serpents upon land ; as it is indeed well ascertained, 
that some serpentiform fishes, especially the true murtenas, 
are capable of transferring with great effect, their aquatic 
locomotive powers to the surface of the earth. In what 
manner its enormous pouch is employed in its economy, I 
repeat, that I cannot presume to determine ; its complete 
inflation with air, when on the surface, must, it would appear, 
afford a very effectual obstacle to the descent of the animal 
beneath. Whether it be capable of secreting the contained 
air, as has been thought of the common internal air vesicles 
of some other fishes, for which apparent purpose, eels have 
a peculiar gland connected with its centre, or whether water 
be allowed to enter its cavity, as it has been thought to enter 
the abdominal cavity of some rays, would form a subject of 
interesting enquiry. Having however entered on the field 
of conjecture, I shall not presume to longer engage the 
attention of the Royal Society, though I cannot but express a 
hope, that the discovery of another curious link in the vast 
chain of being, and especially in latitudes where such an one 
might have been least expected, will be considered sufficiently 
important to merit their notice. 
Royal Institution, Jan. 10, 1827. 
MDCCCXXVII. 
I 
