225 ALICE L. EMBLETON ON A NEW 
of the surrounding tissue. On examining the contents of the 
rectum, I found that it contained immense numbers of these 
Infusorians, but having only preserved material at my disposal I 
was unable to investigate more than the most salient features; in 
fact, to make out these points many different reagents and stains 
had to be used. On the whole, I found it best to first clear the 
material of corrosive sublimate by immersion in iodine solution, 
then stain with alum-carmine, finally clearing in oil of cloves. 
As is seen in fig. 20, the form of the body is quite spherical 
when looked at from above (as in i.) or from below; iu. shows a 
lateral view. It is not easy to say without watching living speci- 
mens, or at least examining fresh material, which is the anterior 
and which the posterior end. Above and below there is a circlet 
of cilia; at one end they encircle a depressed pit-like area around 
which there seemed to be signs of a skeletal ring of spines or 
hooks (ii., 2). At the opposite end the cilia surround a dome-like 
protuberance—which may, however, have been thus forced out 
as a result of post-mortem contraction. In the rim in which the 
set of cilia are inserted, I saw, in many specimeus, indications of 
a gullet, or esophagus ; this would point to the fact that this is 
the anterior end, which would go first in swimming. Situated 
just beneath this crown of cilia there is an enormous darkly- 
staining nucleus; it is very long and constricted at intervals so: 
as to look like a string of beads (zc). 
A clear spot was present near the nucleus, whick may be the 
contractile vacuole, or a reservoir (ve). 
So far as [ can form an opinion from the material at my 
disposal, this is a new species of Zrichodina, a peretrichous 
Infusorian related to Vorticella. ‘The common species is found 
creeping about the surface of Hydre; but I find that a repre- 
sentative of the genus has been met with (by Rosseter *), living 
an endoparasitic life in the viscera of the newt; very few were 
found in the testes, but myriads occurred in the renal organs— 
it is stated that long dearth of water in no way hurts them.. 
This Japanese species may be identical with the form occurring 
in the newt, for it also leads a truly entozoic life within the 
rectum of its host ; but as this alone is not sufficient to justity 
the application of a new specific name, I prefer to leave the 
question of species open, pending a fuller knowledge of the 
creature and of the habits of the accepted species of the genus. 
Cambridge, Nov. 1900. 
* Journ. R. Mier. Soc. vi, (2) pp. 929-938, 1 pl. 
