CLASS PISCES. 565 



swallowing the air, and rilling their stomach with 

 that fluid, or rather filling a sort of crop, very thin, 

 and very extensible, which occupies the whole length 

 of the abdomen, adhering intimately to the peri- 

 toneum, which has caused it to be sometimes taken 

 for the peritoneum itself, sometimes for a sort of 

 epiploon. When they are thus inflated, they turn 

 on their backs ; the belly is uppermost, and they float 

 on the surface of the water, without being capable of 

 directing themselves. But this constitutes for them a 

 means of defence, because the spines with which their 

 skin is furnished are then raised on all sides \ They 

 have, moreover, an air-bladder with two lobes ; their 

 kidneys, situated very high, have been erroneously 

 taken for lungs 2 . They have but three gills on each 

 side 3 . They utter, when they are taken, a sound, 

 which is certainly caused by the air which issues from 

 their stomach. Their nostrils are furnished each with 

 a double fleshy tentaculum. 



1 See Geoffroy St. Hilaire, Desc. des Poissons d'Egypte, in the 

 great work on Egypt. There are also analogous dispositions in the 

 chironectes. 



2 It is thus that I think I can explain the error of Schcepf. Ecrits. 

 des Nat. de Berlin, viii. 190, and that of Plumier, Schn. 513, and 

 without doubt, also that of Garden., Lin. Syst. ed. XII. i. p. 348, 

 in notis. As for the cellular organs of which Broussonet speaks, 

 Ac. des Soc. 1780, last page, there is nothing which can give rise 

 to such a supposition. It is certain that these fishes differ in no re- 

 spect from others in the mode of respiration. 



3 We have already had an example of this number in Lophius. 



