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THE SEA-URCHINS*. 



The Sea-urchins are generally round, and shaped 

 like a somewhat flattened ball. Their exterior is a 

 bony crust, usually furnished with moveable spines, 

 by which they are defended from injury, and by 

 means of which they have their progressive motion: 

 these are often very numerous, amounting in some 

 species to upwards of two thousand. The mouth is 

 placed beneath, and in most of the species has five 

 valves or teeth. 



They are all inhabitants of the sea, and, in their 

 general character, have so great an alliance to each 

 other that it will not be necessary to bring for- 

 ward more than one species, to illustrate the whole 

 tribe, 



THE COMMON SEA-URCHI N f. 



This animal, which lodges in cavities of rocks just 

 within low-water mark, on most of the British coasts, 

 js nearly of a globular shape, having its shell marked 

 into ten partitions or divisions, not much unlike those 

 of an orange. The mouth is situated in the lower or 

 under part, and armed with five strong and sharpened 

 teeth. The stomach and intestines, which are of 

 considerable length, are disposed in a somewhat cir- 



* Sea Hedge-hogs or Sea Eggs. 



-f- Synonyms. — Echinus esculentus. Linn.— Eatable Echinus. 

 /V/j>z.— — - Common Echinus, or Esculent Echinus.— —-Shaw's Nat. 

 Mis. 



