THE BOTTLE ANIMALCULE, FOLLICULINA. 263 



of four hundred meters. A few were taken on the surface of 

 the water. 



There are, however, records of its occurrence in fresh waters; 

 thus Saville Kent in England described Folliculina boltoni 

 from Anadiaris and other plants as living in fresh water, and 

 Barrett found it in the fresh waters of the Thames; while the 

 form called Ascobius lentus by Henneguey in France found in 

 flowing fresh water in the botanic garden at Montpelier on the 

 leaves of Aponogeton dystachium seems to be a kind of Folliculina. 



The Folliculina found in the Severn are no doubt Folliculina 

 ampulla in the wide sense used by Stein and by Mobius and 

 resemble most the forms described by Strethill Wright, but in 

 the light of the revision of the group by Carl Dons the specific 

 determination of these Severn forms is deferred till a more 

 complete comprehension of their life history furnish a better 



Fie. i. Side view of case made by Folliculina. Camera lucida. X 233. 



basis than the mere form of secreted case the animal inhabits. 

 Both Folliculina and Parafolliculina forms in the sense used by 

 Dons occur here; but the character of nucleus and existence of 

 micronucleus necessitates much modification in his classifications. 

 It may well be that not only Freia and Lagotia but also Ascobius 

 are synonyms of Folluculina and that many of the species are 

 but phases in a protean life cycle. 



The most usual form of dwelling inhabited by Folliculina in 

 the Severn is shown in Fig. I enlarged 233 diameters. For con- 

 venience of description it might be regarded as made up of a 

 sac and a tube, both together constituting the case. The sac 

 is the part of the case attached to some foreign object and the 

 tube is the free part. The sac is wider from side to side than it is 



