288 Transactions of the Society. 



like to consider the mouth, or rather to discuss the question of 

 its existence at all. S. Kent, in his Arachnidium, indicates: 

 "oral aperture terminal, central"; but it is quite possible, if 

 at least Kent's Araclmidmm really belongs to the same group as 

 Araclinidiopsis, that the author might have taken for an oral 

 aperture what was simply a rounded space encircled with a 

 wreath of tentacles. In our Arachnidiopsis the first impression 

 is that of an aperture, even very distinct and sharp (figs. 2, 3) ; 

 but on better examination one must arrive at quite another 

 conclusion : this fissure-like, or 8-shaped, appearance as shown 

 on the animal seen from above (fig. 3), or this excavation as in 

 fig. 2, is certainly nothing but the base of the tentacles. A real 

 mouth does not seem to exist ; at any rate, I never found any 

 indication of it. 



But then, how does the animal take its food ? It is surely an 

 Infusorian, perfect and complete, with its nucleus and contractile 

 vesicle, and with food-particles everywhere disseminated in the 

 body. 



Unluckily, this question must remain unanswered ; all my 

 searches ended in the total acquisition of three specimens, and 

 none of them was seen capturing food. But if my ignorance has 

 remained complete on this point, yet I may be allowed to indicate, 

 as a simple but perhaps not very improbable hypothesis, some sup- 

 positions which real facts induce me to entertain. These facts are 

 the following : — 



1. The animal is, or seems to be, naked ; perhaps with a mere 

 hardening of its ectoplasm into a fine pellicle. 



2. The posterior extremity of the body certainly shows a certain 

 degree of viscosity, and at the same time is capable of deformation, 

 emitting at times a small lobe or knob which might recall what 

 we see, for instance, in some Amoebae. 



3. In fig. 4 one can see, at the left and just under the basis of 

 one of the tentacles, a very small knob or prominence, and within 

 one small black particle. Now, this prominence was to be seen on 

 the living animal as a small knob of clear protoplasm with a 

 brownish granule. 



Might we not be entitled, then, to suppose the capture of food 

 in the form of small particles coming from outside, perhaps thrown 

 against the viscous surface of the body by the movements of the 

 tentacular organs, and then drawn inside the cytoplasm ? 



This, of course, is pure supposition, but in the absence of any 

 indication of an oral aperture any hypothesis may be put forward,, 

 provided it is given as such. 



A few words more about the position which must be assigned 

 to Arachnidiopsis, as well perhaps as to Arachnidium, in the 

 classification of lower organisms. 



The class Infusoria is generally considered as comprising two 



