Apodal Fishes of Bengal. 163 



are very strong and bony, in others long, slender, and car- 

 tilaginous; in others soft and thread-like, and so slender 

 as to be scarcely perceptible. They are, however, as well 

 as the operculum always present, but occasionally in so slight 

 a degree, as to render their utility in the economy of some 

 species very doubtful. 



4. Dentition. — The teeth are generally disposed in rows 

 and bands, except in one or two genera in which they are 

 crowded. They are disposed on either side of both jaws. 

 The bones on which the teeth are situated are the palatines, 

 maxillaries, intermaxillaries, lower maxilla, and vomer ; to- 

 gether with the pharangeal bones connected with the last 

 branchial arch. 



These bones undergo a great diversity of form, produc- 

 ing corresponding changes in the distribution and situ- 

 ation of the teeth ; the most important of which is, the con- 

 traction of breadth in the palatines of Murcenidce. Generally 

 throughout the order, wherever there is but a single row 

 of teeth on the edge of the upper jaw, that row is planted 

 on the maxillaries. The palatine teeth in such cases oc- 

 cupy a position corresponding with those of the vomer in 

 other orders. 



There are usually four clusters or rows of minute teeth, 

 situated at the entrance of the oesophagus. The teeth are 

 conical, rather short and obtuse in some ; long, sharp and 

 slender in others, and generally slightly hooked or recurved 

 towards the points. 



In some, the vomer teeth are compressed ; in others, 

 conical. This last kind are sometimes fixed to a moveable 

 pedicle, and are capable of being retracted or drawn flat down 

 upon the jaws. This peculiarity, if it exists in European 

 species at all, has hitherto been overlooked by naturalists. 



5. Colour. — This is generally connected with the scales 

 of fishes. The species composing the order now under 

 review, have been generally supposed to present their scales 



