592 DESCRIPTION or {Polygastrica. 



three genera, but no gemmae or buds. Eyes have not been de- 

 tected. 



r brow without horns Oxytricha. 



Cilia and setcB— no styles or uncini "1 , ,, , _ ^.,. 



L urow with horns Ceratidiuni, 



["with uncini — no styles Kerona. 



Styles, or uncini, or both J with styles— no uncini TJrostyla. 



[_with styles and uncini Stylonychia. 



This family Oxytrichina is generally similar to the Keroniens of 

 Dujardin, a family of animalcules, according to this observer, much 

 lower in the scale than many in the families previously described, 

 such as Kolpoda, Paramecium, Coleps, &c. 



" Processes in the form of styles or hooks, characterise both the 

 ' Keroniens' and the ' Ploesconiens,' but the latter have a shield 

 (lorica), whilst the former are soft, and have no sign of an inte- 

 gument. Of the 'Keroniens,' the Oxytricha have no horns or hooks, 

 but only cirrhi or straight processes, and in appearance rigid ; 

 another genus, ' Haltei'iaj' has large cirrhi like the preceding, but 

 differs considerably in its mode of life and its movements. 



"The TJrostyla of Ehrenberg, with styles only and no hooks 

 (uncini), we unite with Oxytricha, and his Stylonychia, provided 

 with both styles and hooks, with Kerona ; another genus described 

 by Ehrenberg under the name of Ceratidium, horned anteriorly, but 

 wanting both styles and hooks, seems to be but altered or mutilated 

 Keronce. On the other hand the Halteria appear to be included 

 by Ehrenberg among true JJrceolai-iu, in his genus Trichodina, 

 although it possesses none of the characters. The Keroniens are 

 found in stagnant water, fresh and salt." 



Genus Oxytricha. — The hatchet Animalcules are destitute of 

 styles and uncini, and unprovided with horns. The body is soft, 

 flexible, oval or oblong, and more or less flattened. They possess 

 cUia and setse, the latter resembling rigid hairs ; their movements 

 are forwards and backwards, often by impulses, creeping, swimming, 

 and climbing ; locomotion is effected by the cilia. In all the species 

 polygastric cells are evident, in five ova-like granules, in four male 

 glands, and in five round sexual vesicles. Transverse and longitudinal 

 division is observed in O. lepus and O. pelionella s longitudinal only 



