ANOMALOUS CARTILAGINOUS FISHES. 317 



larger than the swan's quill, yet it measures upwards 

 of sixteen inches in length ; its general colour is an 

 olive brown, marked with a number of bluish lines, 

 taking a direction from the belly to the back. 



The hippocampus, which, from the form of its head, 

 has been termed the sea-horse, never exceeds nine 

 inches in length, and in thickness is about the size of 

 a man's thumb : the snout is a sort of tube with a hole 

 at the bottom, the cover of which the animal can shut 

 or open at its will ; behind the eyes are two erect fins 

 that have the appearance of ears, and the whole body 

 seems composed of cartilaginous rings, on the inter- 

 mediate membranes of which several small prickles are 

 placed. The hippocampus is found on the Mediter- 

 ranean shores, and bears a greater resemblance to a 

 caterpillar than a fish. 



From these harmless animals, covered with a slight 

 coat of mail, w r e may proceed to others more thickly 

 defended, whose exact station in the scale of being has 

 not positively been ascertained. In the first of this 

 tribe we may place the sea-orb, which in form is nearly 

 circular; but the size so completely varies, that some 

 are only seven inches, whilst others frequently measure 

 two feet. This animal is sometimes termed the sea- 

 porcupine, from its skin being covered with long 

 prickles or thorns ; and when it is enraged, these wea- 

 pons are erected, and, by inflating a bladder in the 

 stomach, the fish appears almost double its size. 



Of this extraordinary creature there are several va- 

 rieties, some threatening only with spines, as the sea 

 hedge-hog ; others defended with a bony helmet, as the 

 ostracion ; others with a coat of mail from the head to 

 the tail, where it terminates in a point, as the centriscus; 

 and others armed offensively and defensively, with bone* 



