268 DESCRIPTION OF [Polyyastrica. 



what yellow beneath the microscope ; it is very much 

 like the preceding, is often found with it, but is distin- 

 guished by being larger, by its ring-like folds when con- 

 tracted, and by the tasselled or tufted appearance of the 

 cluster. Size 1- 280th to l-210th. 



408. EPISTYLIS grandis. The great Epistylis. Body 

 broadly campanulate, stalk decumbent, slender, smooth, 

 the branches flexible and without articulations, but much 

 tufted. This is not only the largest fresh water species of 

 Epistylis, but it also forms the greatest masses. Its proper 

 colour is a blueish- white, but it often appears of a yellow 

 or greenish hue, from the colour of its food. Found upon 

 Ceratophylla and Nymphaea, often in masses several feet 

 long, and two to three inches thick; it appears like a 

 blueish-white slime, which is easily broken up. Size 

 l-140th to l-120th. 



409. EPISTYLIS flavicans (V. acinosa et belis, M.) 

 The yellowish Epistylis. Body large, broadly campanu- 

 late, pedicle smooth, and the branches coarctate. The 

 branches are dilated at the axillae, and the ova are of a 

 yellow colour. In this species, the alimentary canal is 

 very evident. Size (stretched out) l-190th ; tree l-9th 

 high. 



410. EPISTYLIS leucoa (Volvox sphaerula, M.) The 

 while granulated Epistylis has the body large, broadly 

 campanulate, pedicle erect, smooth, and articulated ; the 

 branches are capitate, or collected in a head; the ova 

 white. These animalcules are convex anteriorly, have 

 distinct ova granules, a simple wreath of cilii, and a round 

 mouth at the margin. The seminal gland is bent in the 

 form of the letter S. Size l-120th; tree l-24th; ova 



