46'() GYMNODONTIDjE. 



" The fish, having remained in this distended state for a 

 short time, generally expelled the air and water with consi- 

 derable force from the branchial apertures and mouth. It 

 could emit, at will, a certain portion of the water ; and it 

 appears, therefore, probable that this fluid is taken in partly 

 for the sake of regulating its specific gravity. This Diodon 

 possessed several means of defence. It could give a severe 

 bite, and could eject water from its mouth to some distance, 

 at the same time it made a curious noise by the movement of 

 its jaws. By the inflation of its body, the papillse, with 

 which the skin is covered, became erect and pointed. But 

 the most curious circumstance was, that it emitted from the 

 skin of its belly, when handled, a most beautiful carmine red 

 and fibrous secretion, which stained ivory and paper in so 

 permanent a manner, that the tint is retained with all its 

 brightness to the present day. I am quite ignorant of the 

 nature and use of this secretion." 



The vignette is copied, on a very reduced scale, from one 

 of the illustrations published in the Catalogue of the Museum 

 of the Royal College of Surgeons in London, and is thus 

 described : " The figure in this plate is taken from the 

 large specimen of Crop-fish, or Globe-fish (Tetrodon Pen- 

 nantii, Yarrell). The abdominal parietes, and those of the 

 cesophageal dilatation forming the air-bag, are laid open to 

 show the smooth internal surface of the air-bag ; the anterior 

 opening into the first oesophagus, and the valvular passage to 

 the second esophagus." 



Pennant's fish measured one foot seven inches in length ; 

 the belly when distended, one foot ; the whole circumference 

 when in that state, two feet six inches. The form of the 

 body is usually oblong ; but when alarmed, it assumes the 

 shape which has been already referred to. The mouth is 

 small ; the irides white, tinged with red ; the back from head 

 to tail almost straight, or at least very slightly elevated ; 



