170 SEA URCHIN. 



and smooth; the head large, and depressed at the top ; and 

 in the hind part are two orifices through which it breathes, 

 and ejects the water received by its mouth, after the manner 

 of cetaceous fishes. The aperture of the gills are closed ; 

 and on the extremity of each of the bones which covers 

 them, is a very singular trifurcated spine. The upper jaw 

 projects much farther than the lower, and the teeth are 

 very minute, though the mouth is extremely large. 



The colours of this fish exhibit a delightful variety of 

 yellow, blue, and white ; the blue, in particular, is incon- 

 ceivably beautiful, and glows with a lustre little inferior to 

 that of the diamond. Pontoppidan calls this species the 

 flying fish ; but, whether it makes use of its fins as the 

 means of elevating itself out of the water, is a circumstance 

 which has not yet been satisfactorily ascertained. 



THE COMMON SEA-URCHIN 



Is very frequent on many of our own coasts. It is slightly 

 flattened beneath, and often measures four inches in 

 diameter. The body within the shell is divided into lobes, 

 something like an orange ; the intestines are disposed in a 

 circular direction, and the whole body is supported by 

 bony columns. The shell is of a dull violet, or greenish 

 colour, and is beset with a multitude of sharp spines, 

 moveable, and jointed into the turbercles of the surface, 

 to which they are also attached by strong ligaments. 

 These spines are the organs of motion, by means of which 

 the animal changes its place at pleasure ; while it fastens 

 itself to any particular object, by feelers issuing from 

 numerous small holes between the tubercles ; these feelers 

 are also employed in conveying the food to the mouth of 

 the animal. The Sea-Urchin is extremely tenacious of 

 the vital principle. Many of the Sea-Urchins, especially 

 those of the Indian seas, are highly curious ; and, in all, 

 the shell, divested of its spines, presents a beautiful appear- 

 ance, from the lacy structure of the hole, and the pearly 

 colour of the tubercles. 



