PHILODINA. 105 



{iiicl said to be "cervical." Tlie clianges of form 

 in this rotifer are still more remarkable than in 

 the common wheel-bearer. When resting it resem- 

 bles a pear-shaped purse, puckered in at the mouth. 

 Then it thrusts out its tail-foot, swells its body to 

 an oval globe, protrudes its feeler, and slightly 

 exposes a row of cilia. After this two distinct 

 wheels are everted, and as their cilia whirl and 

 spin, the animal is swiftly rowed along, until it 

 thinks proper to moor itself fast by the tail -foot. 



Philoclina- cruMlinff. 



and employ all its ciliary power in causing currents 

 to converge towards its throat. AVhen it pleases 

 it can elongate the body, till it becomes vermiform, 

 and it walks like the common rotifer, by curving 

 its back, and bringing its nose and its tail in 

 contact with the ground. 



The gizzard of this family (Philodmoeo) presents 

 a considerable deviation from the perfect form ex- 

 hibited by the Brachions. According to Mr. Gosse, 

 "The niallci and the inciis (terms already explained,) 



