XX. 



THERE is a very singular group of animals, tlie 

 Holothuriadce, that claims a passing notice, from 

 their near relation in structural formation to the 

 Sea-Urchins, although externally they also exhibit 

 a certain resemblance to the Annelides. They are 

 commonly termed Sea-Cucumbers, from the fancied 

 likeness which they bear, both in shape and colour, 

 to their namesakes of the vegetable kingdom. 



A Holothuria is very unattractive in appearance 

 when lying listless upon the sea-beach, but if a small 

 specimen be transferred to the aquarium, it exhibits 

 features of a very singular and interesting character. 

 When about to change its position, the head, hitherto 

 concealed, is protruded and expanded, until it assumes 

 the form of a beautiful flower. 



The animal moves principally by aid of sucker- 

 like feet, similar in form to those of the Asteriadse, 

 or Sea-Urchins. In most species, the body is divided 

 longitudinally into five rows of suckers. In some, 

 however, these organs are scattered over the entire 



