Apodal Fishes of Bengal. 189 



by creating two long distinct cavities in the trunk, as 

 in animals provided with lungs, instead of a single ca- 

 vity as in other fishes. The abdomen being removed 

 back to make way for a lengthened thorax, occupied only 

 by the branchial arteries, oesophagus, and heart ; the 

 intestinal outlet is carried back to the latter third of the 

 body. The tail is consequently short. The membranous 

 expansion representing the dorsal fin, advances a little in 

 front of the ventral aperture. There is no air-vessel in 

 any of the species of Bengal, although Cuvier states, that 

 in the genus Synbranchus, Bl., that organ is fully deve- 

 loped. In some, the stomach is a cul-de-sac, with the 

 intestine given off in front as in Anguilliformes ; in others, 

 it is continuous with the stomach, and together with that 

 organ, forms a straight tube extending from the oeso- 

 phagus to the vent. The liver is very long and narrow ; 

 in some, it is chiefly developed at the further extremity 

 of the abdomen ; in others it occupies the usual position 

 behind the midrif ; but notwithstanding such apparent 

 transposition of this organ, its attachment to the lower 

 surface of the midrif appears to be an universal condition 

 in all animals ; and in this instance the difference is merely 

 in the increased length of the capsular ligament. 



In all the species, the entrance to the oesophagus is guarded 

 by two groups of very small, but sharp pharangeal teeth on 

 either side. 



The gills undergo many singular modifications in this 

 tribe. 



In some, they are without bony arches; in others while 

 bony arches are present, they are almost destitute of pectina- 

 ted combs. In some, the gills on either side are contained in 

 two distinct cavities ; in others, both gills are contained in 

 one common cavity. In some, the want of pectinated combs 

 or gills, is supplied by a membranous sack, by which the func- 

 tions of respiration are effected. 



