THE RED GURNAHD. S7 



in the outline appended as a vignette to that fish ; in other 

 Gurnards it is bilobed, but not very deeply cleft at the 

 anterior part : the common Red Gurnard, the subject of the 

 present notice, and the Grey Gurnard, are instances. In the 

 Salmon, the Herring, and the Eel tribes, it is one elongated 

 cylindrical tube, lying close to the under surface of the 

 backbone. In the Sciana aquila, the edges of the single- 

 chambered swimming-bladder of that fish are fringed all 

 round, of which a representation will be added ; but in 

 the Carp, this organ is formed of two oblong cavities, the 

 larger one lying behind the other, and communicating by 

 an aperture in the neck or narrow portion connecting the 

 two parts. From the anterior surface of the posterior lobe 

 in the Carp, (a section of the whole subject reduced in size 

 from Monro''s Anatomy of Fishes being here added, with a 

 probe introduced through the aperture in the neck, to 

 show the communication between the two chambers,) a 

 tube is given oflT, which, passing forwards, opens into the 

 oesophagus, but is closed against the admission of any ex- 

 traneous bodies by a delicate valve, which can only be passed 

 in the outward direction. 



The air-bladders are usually made up of two membranes. 

 The inner one has a moist, smooth, and, apparently, a se- 

 creting surface ; the outer membrane is fibrous in its struc- 

 ture, and a portion of the bladder is in some species in- 

 vested by a fold of the peritoneum : the three coats, when 



