FRESHWATER LIFE INFUSORIA. 323 



Peridinium may be cited as a good example of the Flagellata. My 

 specimens, got from a clay-pit in December, were of a rich Indian yellow 

 hue, about l-300th of an inch long, furnished with a belt of active ciha 

 running round the middle, a minute mouth near the centi-e, and on one 

 side of the mouth a lithe filament, the so-called flagellum. Pro-vided 

 with such ample means of locomotion, the little acrobats kept up their 

 roUiug and tumbhug movements with untiring \'igour. I watched them 

 at all hours, and never caught them reposing. My belief is that they 

 never once rested from birth to death. 



I shall not add any remarks upon the TentacuUfera, about which 

 competent opinions are as yet divided. All who are interested in the 

 microscopic forms of Freshwater Life must hail with expectation Mr. 

 Saville Kent's new book on the Infusoria, a work which, side by side with 

 other well-known authorities, cannot fail to be of gi'eat assistance to the 

 student. 



HELIX CANTLiNA, (Montagu.) 



Since Martin Lister, in the latter part of the seventeenth century, 

 indicated the existence of this MoUusk, which, he thought, might be 

 a variety of H. rufescens, or a distinct species, giving as its habitat 

 " Kent," an almost complete knowledge of the Mollusks inhabiting 

 Britain has been attained, and it is of much interest to Conchologists to 

 note the distribution of species over these Islands. 



Montagu, in 1803, called it Cantiana, after its early recorded 

 habitat. We know now that it occurs not only in the south and south- 

 eastern counties, but has spread northward and westward, following the 

 theoretical line of migration of the Mollusca of this country. 



We have authentic records of its occuri'ence in twenty-one counties — 

 twenty in England and one in Wales, as follows : — Sussex, SuiTey, Kent, 

 Middlesex, Hants, Somerset, Essex, Heriford, Oxford, Gloucester, 

 Monmouth, Suffolk, Warwick, Worcester, Cambridge, Norfolk, Stafford, 

 Lincoln, Yorkshire, Northumberland, and Glamorgan. This being the 

 case, we should expect to find it in the central counties of Buckingham, 

 Bedford, Huntingdon, Leicester, Northampton, Nottingham, and Derby ; 

 and southward in Berks, Wilts, and Dorset. 



If any of our friends, while reading these notes, will take the map of 

 England, they will readily see that, with three exceptions, the counties 

 eniimerated as habitats, are contiguous ; and whether we ascribe its 

 distribution to the creature's own powers of migration, or to man's agency, 

 the result is the same ; and we should scarcely expect that, in its spread, 

 it would skirt the eastern coast from the south, and travel from south up 

 the central counties, and miss those indicated. 



It will be of much interest if any of our fi-iends, having observed it 

 in any of the counties named, would kindly inform us of the fact. 



In our own district it occurs at Henley-in-Arden, where it was first 

 observed by Mr. W. G. Blatch ; and we have, during one of our pleasant 



