308 NOTES ON SOME CANADIAN INFUSORIA. 



other will give a quick sudden jump, settling to repose again almost 

 immediately. 



C. margaritaceum (fig. 4) differs from the preceding in many 

 respects. It presents the same hood-shaped structure (h) at the 

 mouth, which is in the same position, but the hood is not nearly as 

 large as that of G. glaucoma. It is somewhat large, measuring 

 0.024 mm., presents a somewhat pearly appearance, and is covered 

 with minute tubercles. The arrangement of the cilia is also very 

 different, the anterior three-fourths being covered with ordinary small 

 cilia, while at the posterior extremity are a few setae. It is con- 

 stantly in motion, seldom resting, and never moving in the quick 

 jerky manner characteristic of the other form. 



The two following forms I observed in water from the University 

 creek, Toronto, which had been allowed to stand for some time, and 

 was almost destitute of green matter. 



VORTICiLLA MICROSTOMA, EHERH. 



The striations in this form (fig. 5) are not easily seen, but may be 

 observed most readily under oblique illumination. My object in 

 mentioning it is to confirm, or rather partially confirm, a phenomenon 

 observed by Kent. While watching one of these animalcules, I 

 observed it suddenly leave the stalk, which immediately contracted, 

 and swim away by means of the cilia of the disc, not developing a 

 posterior circle as is usual in such cases. The consequences of this 

 action I was unable to follow, as by the next morning the animal 

 was dead. Kent, however, has been able to follow it farther, and 

 states that it encysts, the cyst having a characteristic appearance. 



ENGLENA ACUS, EHERH. 



This form (fig. 6) occurred in considerable abundance. It was 

 0.126 mm. in length, and is mentioned on account of the entire 

 absence of the green colouring matter which usually characterizes all 

 members of this genus. The red eye-spot (e) was however plainly 

 visible. This was probably owing to their not being able to procure 

 their accustomed food. Kent, in 1880, received specimens from 

 near Birmingham, averaging 0.169 mm. in length, which presented 

 the same peculiarity, which he attributes to the above mentioned 

 cause. His forms were all exceedingly attenuate and stiff in their 

 motions. Certain of the forms I observed were capable of consid- 



