160 DESCRIPTION OF [Pol^cfastrica. 



otlier, with their tails radiating from the centre, and by means of 

 which each animalcule is fixed to the base of its own special en- 

 velope. Each one is furnished with a filiform proboscis, which gives 

 to the entire group the appearance of being covered with hairs. 

 When the creatui'es divide, the mantle or lacema, only enlarges, 

 without becoming separated itself. The visual organ is a red speck 

 iu the fore part of the body ; the tail is fiiliform, resembling that of 

 Vorticella mid Bodo. 



The internal structure of these compound animalcules can be ve- 

 rified only with instruments of superior quality, and require con- 

 siderable skill in the management of them. This latter qualification 

 is so indispensable, that notwithstanding many persons in this 

 country possess better microscopes than those employed by Ehren- 

 bcrg, the curious organization of these little creatures has hitherto 

 eluded their observation. 



Ueoglena vokox. — Body composed of yellow corpuscles of an ob- 

 long fonn. Tail extensible from three to six times the length of the 

 body, and even more. Cluster mulberry-shaped. There is little 

 doubt but that single animalcules of this genus, seen in company 

 with the clusters, have often been taken for creatures of a different 

 family. Ehrenberg states that he has observed iadividuals with two 

 or three eyes, which he conceives to have been a symptom of ap- 

 proaching self- division. Eig. 54 gives a magnified representation of 

 a globular cluster of these animalcules, and fig. 53 a single one, in 

 which the red eye is distinctly visible. Found in turf water. 

 Diameter of cluster. l-90th. 



Genus Eudoeina. The globe Animalcule with an eye. — The cha- 

 racteristics of this genus are its absence of tail, but possession of the 

 eye, which may be distinctly seen, and a simple filifonn vibratory 

 proboscis, situated at the mouth, as its organ of locomotion, &c. 

 SeU'-di\dsion is also undergone by the individuals simply and equally, 

 whilst retaining their dusted position. These little creatures are 

 endowed with the power of periodically casting off their globular 

 lorica or mantle {lacema) which envelopes the cluster, and exuding 

 a new one, like certain animals of the class Annelida. To observe 

 the eye a power of 300 diameters must be skilfully employed. 



E. eleyans. — Composed of green corpuscles, of a globular shape, 



