OF ANIMALCULES. 81 



GENUS VI. 



CYCLIDIUM. 



This genus is composed of animalcules of a flat, round, 

 or oval form, without any apparent cilia. Like some 

 others, they are so very diaphanous that the most deli- 

 cately finished engravings of them afford but a faint idea 

 of their exquisitely brilliant, crystal-like appearance, 

 when viewed under a good Achromatic Microscope of 

 large angular aperture. 



130. Cyclidium bulla. The bubble Ci/clidium. — This 

 animalcule is very diaphanous, and of a circular form. 

 By careful observation, small sacs may be discerned 

 within it. It swims in a graceful serpentine course. 

 Found in an infusion of hay. 



131. Clyclidium milium. The millet Cyclidium. — 

 This species is very minute, and, under moderate am- 

 plification, appears like millet-seed ; but with a deej) 

 magnifier its elliptic figure is readily seen, and its bril- 

 liant, crystal-like appearance, combined with the variety 

 of its movements, render it a most interesting micro- 

 scopic object. A few sacs may be seen occasionally in 

 its interior ; from the currents it sometimes produces in 

 the water, the body must be furnished with cilia. 



