DtTBLIN NATUEil HISTOEY SOCIETY. 5 



the diied specimen (fig. 3). At the sometime that the opening of the mouth 

 is enlarged, the capacity of the throat is widened. The long fork, or 

 process, consists of two limbs, as already described, uniting at an angle 

 in the centre. The same muscular action which draws back the point 

 of junction in drawing it downwards and away from the lower jaw, 

 widens the whole extent of the pipe-lil^e mouth ; but it does more than 

 this, for by the same action the two lips of the bony fork, or derrick, are 

 made to diverge ; and iu so doing the throat of the fish is also enlarged 

 laterally, and to double its former size. In an ordinary-sized 'Syn- 

 gnathus the jaw measures about a quarter of an inch across when the 

 bony fork is lying in its receptacle, but when the fork is in action and 

 out at its full extent at right angles to the jaw, its limbs diverge until 

 it separates the jaws to the extent of half an inch. The Syngnathus 

 may be watched a long time in confinement before the action of this ap- 

 paratus is seen. Sometimes one's patience is quite worn out watching 

 for it ; at other times the action is seen several times in a minute, and 

 it is then beautiful to observe with the action and projection of the bony 

 derrick the simultaneous drawing down of the lip and the widening of 

 the long pipe-like mouth and throat. 



In this mechanism there is an antagonism of ligamentary and mus- 

 cular action, the elastic ligament drawing down and retaining the point 

 of the bony fork in its receptacle within the angle of the jaw, the mus- 

 cular action elevating it when required to aid the action of swallowing. 

 In the dead animal the elastic action continuing the bony fork is re- 

 tained in its receptacle, and escapes observation. In the living animal, 

 however, this bony process and its action may be easily demonstrated, 

 by gently bending back the head of the fish, and raising the point of the 

 process with the nail or a fijie edge, and it will then be seen that, while 

 thus retained, the mouth is opened wide, and cannot be shut. 



Dr. Mayne has drawn my attention to an antagonism of muscular 

 action and ligamentary elasticity in the larynx of the Porpoise, similar 

 to that which exists in the jaw mechanism in the Syngnathus. In tho 

 poi-poise an elastic action keeps the larynx closed without any effort on 

 the part of the animal until it rises to breathe at the surface, when a 

 muscular action comes into play, and, for the moment, opens the larynx 

 to permit the ingress of air. 



The Syngnathus is one of our most interesting fishes in a vivarium, 

 so singular in appearance, so different from all other order of fishes, and 

 so vivid in the contrast of its colours, and so cased in armour. It is at 

 fii'st very wild, and, unless the vivarium be covered, will almost cer- 

 tainly jump over its sides ; but it soon becomes reconciled to confinement, 

 and will, with a' turn or two of its taO, support itself on any stem placed 

 in the vivarium for its support ; or, if there be two of them, they will 

 intertwine their tails in a knot, and raise their h*eads and long slender 

 bodies, side by side, towards the surface, remaining for hours in that 

 posture. In the Syngnathus mquoreus there is no pouch for the recep- 

 tion and protection of the young ; but in ihc other specimen on the table 

 {Symjnathis acus), which I beg also to present to the Society, the pouch 



