XXIIT. 



ON A SPECIES OF CE^TOSPIRA FOUND AT HODDESDON. 



By r. W. Phillips. 



Sead at Hertford, 2oth January, 1881. 



At the meeting held here last March, Mr. Henry "Warner drew a 

 rough sketch of an animalcule, and told me that he had found it 

 many years ago in a pond at the AVoodlands, Hoddesdon, but had 

 never been able to identify it. I saw at once that it corresponded 

 with the drawing of Clmtofpira Miilleri given in the last edition of 

 Pritchard's ' Infusoria.' I had met with it about two years before, 

 but unfortunately had given but little attention to it. I did not 

 find it again until last October, and it was under the following 

 circumstances. Last July I placed in a polype-trough what I 

 judged to be the empty coenoecium of a Polyzoon, and some Paludi- 

 cellce, obtained from the same pond, leaving them there in the hope 

 that statoblasts might be deposited ; about a month after I sent the 

 trough and contents to Mr. Isaac Ilobinson. While it was in his 

 possession some creature laid a number of eggs against the glass, 

 and attention was from time to time directed to their development. 

 One day Mr. Robinson reported the appearance of a strange creature 

 adherent to this egg-case, which was now empty. The description 

 of its movements convinced me that it was no other than the rather 

 rare ChMospira; and on examining it, I found that it was so. The 

 animalcule, which was extremely small, had built its tube or 

 sheath in one of the depressions of the empty egg-case. Unfortu- 

 nately the glass of the polype-trough was too thick to use the 

 i-inch objective, therefore we used the ^-inch objective and D 

 eyepiece ; a power which was insufficient to enable me to make an 

 elaborate investigation. I have the creature still by me, but it is 

 either dead, or encysted, as it has for some time past refused to 

 come out of its tube. The genus appears to be so little known 

 that it would perhaps be advisable to quote Pritchard's description. 

 'Family Vorticellina. "Genus ChMospira (Lachmann). — The sur- 

 face generally covered with cilia, like the genus Stentor, from which 

 it is distinguished by having that part of the parenchyma of the 

 body which bears the ciliary spiral and the anus (which in all the 

 Stentorime lies on the dorsal surface of the body, close under the 

 ciliary spiral, and not in a common pit with the mouth) drawn out 

 into a thin process. This process is narrow and bacillar ; the series 

 of cilia commences at its free extremity, and only forms a spiral 

 when in action, by the rolling-up of the lamina. The process 

 bears the anus. The animalcules inhabit a sheath or tube, of 

 a mucilaginous or even homy density." The genus was first 

 described in 1856 by Mr. Lachmann, who found the two species of 

 which it consists in fresh water near Berlin. They are described 

 by Pritchard as follows : — 



