288 EVENINGS AT THE MICEOSCOPE. 



think them the strongly developed muscles for the re- 

 tractation of the foot. Muscles are seen running 

 through the joints of the foot, imtil they can no longer 

 be traced, from their tenuity. The viscera can be de- 

 monstrated with difficulty, partly owing to the longi- 

 tudinal muscles, which are so strong and close, and 

 partly from the incessant contraction and elongation of 

 the parts, which drive the internal organs hither and 

 thither. It refuses, you see, to swallow carmine, which 

 might have assisted us. 



This singular animal is lively in its motions, espe- 

 cially in the protrusion and retractation of the extremi- 

 ties. These are constantly alternating, and a very cu- 

 rious sight it is to see the immense length of foot sud- 

 denly thrust forth from the body, in which it had been 

 completely hidden, the starting out of the horizontal 

 processes, and the diverging of the long toes as these 

 are successively uncovered. The latter do not seem to 

 be often used as instruments of prehension or adhesion. 

 Indeed the animal does not appear very much given to 

 change of place, but lies in the water, alternately con- 

 tracting and elongating. Frequently, as the foot is 

 thrust out, the body is made to bend forward so as to 

 form a right angle (see the engraving, in which the ani- 

 mal is thus represented at ay i represents it when 

 the head is rotating, but the foot is almost wholly with- 

 drawn within the body ; in which state the resem- 

 blance to a telescope, or to a nest of glass-tubes, is strik- 

 ing). 



The last specimen of this class of tiny favourites 

 that I shall show you, is one of more than ordinary 

 beauty. It is the Two-lipped Tube-wheel of the Horn- 

 wort {Limnias ceratophylli). Hitherto we have seen 



