iS6 



AQUATIC MICROSCOPY FOR BEGINNERS. 



not colored. In its action it resembles Vaginicola and 

 Platycola, being similarly attached to the posterior end 

 of the lorica, and having a similar circle or wreath of 

 cilia around the front border. Two animals are some- 

 times found in one lorica. 



g. St£ntor (Figs. 114, 115, 116). 

 The Stentors vary a good deal in shape in the same 

 species, the bodies of all being at will somewhat 

 changeable in form. .The largest are trumpet-shaped, 

 and are, as a rule, permanently attached to some ob- 

 ject by the narrow end of the body. They also com- 

 monly form a soft, brownish, granular sheath or lorica, 

 to the bottom of which they retreat when disturbed, 

 folding together the wide trumpet-shaped frontal bor- 

 der. 'l"he entire surface of the 

 body in all the species is cili- 

 ated, but the cilia are small 

 and fine. Around the edge of 

 the anterior border is a circle 

 of longer and larger vibratile 

 hairs, visible with a moder- 

 ately low power. The Sten- 

 tors are all common. The fol- 

 lowing Key may help the be- 

 ginner to recognize some of 

 those most frequently seen. 



Key to some species of Stentor. 



1. Attached, trumpet-shaped, 

 and often forming a short, 

 soft granular sheath {a). 



2. Free-swimming, more or 

 less ovoid; green, red, 



Fig. iT4.-stintor poiym6rphus. bluc or-almost blaclc {b). 





