FISHES. 265 



inflated its body, erected its spines, gnashed its teeth, 

 and produced sounds by an emission of air through its 

 mouth. It inflated its body by pumping air into the 

 gullet, by frequent gulps or gasps. The contents of 

 the stomach were fragments of the shells of Hyalcea 

 tridentata, and a sucking-fish, the head of which was 

 detached from the body and much mutilated. The 

 sailor who brought me the specimen, reported that it 

 had also thrown up a sucking-fish at the time it was 

 captured. 



The spines which cover the body of this species are 

 curiously constructed : each spine has a bony root, 

 branched in this manner -< : its longest branch ex- 

 tending horizontally and longitudinally beneath the 

 skin, and the base of the spine being fixed on the angles 

 formed by the two shorter and transverse branches. 

 The long arm of one bony fulcrum invariably overlaps 

 the short branch of another, and thus the entire series 

 forms a very flexible, but at the same time a very com- 

 plete armour. The resemblance which these spines bear 

 to the similar erectile weapons of the porcupine and 

 hedge-hog, amongst quadrupeds, is much increased by 

 the existence of a thick layer of muscle, (or panniculus 

 carnosus,) lining the entire skin of the fish, and firmly 

 attached to the roots of the spines. From the extent 

 of surface this muscle occupies, its power is evidently 

 great; and its use is discovered by handling the in- 

 flated fish : the spines are then necessarily protruded, 

 and press forcibly against any object with which they 

 are in contact ; but their action does not cease here, 

 for the hand holding the inflated animal, feels a con- 

 stant boring motion of the spines, which is extremely 

 painful, and very different from that produced by the 

 passive contact of a thorny body. 



Immediately beneath the muscular lining of the skin, 



