320 DESCRIPTION OF IPolygastricu. 



animalcule in 1820 amongst conferva, but has not lately 

 seen it. It vibrates, runs, and climbs quickly. Figs. 338, 

 339, represent two views of this animalcule. Size l-430th. 



Genus CXXVII. Kerona. The claw Animalcules 

 are provided with cilii and uncini, but not with styles. 

 The body is ciliated, besides which, upon the under sur- 

 face, there are claws, and perhaps setae. Numerous digestive 

 cells indicate the polygastric structure; the mouth, and 

 probably the anal spot, are upon the ventral surface. The 

 propagative system is double, consisting of ova glands, 

 and a contractile vesicle. Self-division has not been 

 observed. 



543. Kerona polyporum. The oval polypi Kerona. — 

 Body whitish, depressed, elliptical, and reniform ; it has 

 a series of cilii around the frontal region, produced from 

 below the mouth; Ehrenberg counted above forty diges- 

 tive cells, many of them filled with brownish (half-digested 

 green) Monads. Between the cells are ova granules. 

 Fig, 340 is a back view, and 341 a side view, climbing. 

 Parasitic on Hydra vulgaris and polypi. (See Microscopic 

 Cabinet, plate vii.) The latter die when infested with them. 

 Size l-144th. 



Genus CXXVIII. Urostyla. The style Animalcules 

 are provided with cilii and styles, but destitute of uncini ; 

 the cilii are thickly disposed in numerous series, those near 

 the mouth being longest. On the ventral surface, at the 

 posterior end, is a small cleft, provided with non-vibratile 

 setas. The numerous digestive cells receive colour and 

 large bodies ; a gland, a contractile sexual vesicle, and 

 delicate granulated ova, represent the propagative system. 

 Transverse self-division also has been observed. 



