164 MICROSCOPY FOll BEGINNERS. 



other division of the group the beginner may not fare 

 so well. 



These have flattened, usually almost opaque bodies, 

 with the entire surface densely clothed by fine cilia, 

 and, probably on account of the stir and disturbance 

 which the cilia make in the water, naturalists have 

 classed the worms together under the name of the Tur- 

 lelldria, from a Latin word meaning a stir or bustle. 

 Their motions are rapid, and apparently without effort. 

 They glide smoothly and swiftly over submerged objects, 

 or swim back downward on the surface of the water. 



There is still another group of common aquatic 

 worms, but to recognize them will give even the begin- 

 ner very little trouble. They are often rather sluggish 

 in their movements. They have a perfectly transparent, 

 smooth, thread-like body, which is apparently truncate 

 in front, and is prolonged posteriorly in a sharpened, 

 point-like tail. They have no bristles nor cilia, and they 

 rather closely resemble a microscopic eel ; indeed the 

 scientific name, Anguillula means a little eel. 



Many members of all these classes are found in the 

 superficial sediment of shallow ponds, in the crevices of 

 wet and water -soaked logs, under submerged stones, 

 among the leaflets of Myriophyllum, Sphagnum, and 

 other water-plants. Sphagnum seems a favorite place 

 for several kinds. I have obtained members of five 

 genera, Ndis, Pristina, Dero, Chcetogdster, and ^Eolo- 

 soma, by placing a little piece of the moss in a watch- 

 glass with a small quantity of water, and gently tearing 



