RESPIRATION IN FISHES. 277 



either into the other cavities, or into the oeso- 

 phagus.* 



In the Myxine, which feeds upon the internal 

 parts of its prey, ^.nd buries its head and part of 

 its body in the flesh, the openings of the respiratory 

 organs are removed sufficiently far from the head to 

 admit of respiration going on while the animal is 

 so employed ; and there are only two external 

 openings, and six lateral pouches on each side, with 

 tubes similar to those in the lamprey. 



The Perca scandens (DaldorfF), |" which is a fish 

 inhabiting the seas of India, has a very remarkable 

 structure, adapting it to the maintenance of respi- 

 ration, and consequently to the support of life for 

 a considerable time when out of the water ; and 

 hence it is said occasionally to travel on land to 

 some distance from the coast. { The pharyngeal 

 bones of this fish have a foliated and cellular struc- 

 ture, which gives them a capacity for retaining a 

 sufficient quantity of water, not only to keep the 

 gills moist, but also to enable them to perform their 

 proper office ; while not a particle of water is suf- 

 fered to escape from them, by the opercula being 

 accurately closed. 



The same faculty, resulting from a similar struc- 

 ture, is possessed by the Op/iicephalus, which is also 

 met with in the lakes and rivers of India and China. 



* It was commonly supposed that the respired water is ejected 

 through the nostril ; but this is certainly a mistake, for the nostril 

 has no communication with the mouth, as was pointed out by Sir 

 E. Home. Phil. Trans, for 1815, p. 259. These organs have also 

 been described by Bloch and Gaertner. 



t Anthias testudineus (Bloch) : Ayiabas (Cuv.) 



X This peculiar faculty has been already alluded to in volume i. 

 p. 386. 



