164- G. J. BURCH ON A SUPPOSED NEW INFUSORIAN. 



diately afterwards, before I could see how it was managed, the 

 food was safely lodged in the creature's throat. 



This was repeated again and again, the particles being gradu- 

 ally forced down towards the central vesicle, at a little distance 

 apart. The conclusion was irresistible, that in some way the 

 creature is conscious of the proximity of something eatable, and 

 catches it by a voluntary effort. The mere action of feeding, 

 enabled me at a glance, to distinguish it from the other Flagellates 

 which I found in the same water. On several occasions particles 

 too large to swallow were caught ; when this happened the 

 flagellum was instantly stretched straight across the head and 

 pressed firmly down ; and if in this way the food could not be 

 forced into the mouth, after three or four seconds it was allowed to 

 escape. 



Not imagining that it might be something new, I made no 

 measurements, but only took a rough sketch with the camera lucida, 

 from which I find that the heads were about half the length of 

 those of Carchesium polypinum. 



Specimens were very plentiful for some weeks. The heads do 

 not apparently break loose from the stems on slight provocation 

 like other Flagellates, for I had one group out of the tank on two 

 successive days, and it was unaltered. With the double spot lens 

 the creatures appear of the usual whitish hue, but with direct sun- 

 light, under a low angled quarter, the heads are of a pale green at 

 the edges and purplish in the centre. 



I made some careful observations with the itli, and came to the 

 conclusion that the cup-shaped depression in the head is bordered 

 with three equidistant prominences, at the base of the largest of 

 which, or from the apex of it— I could not determine which — is the 

 flagellum, and close under the flagellum the opening of the gullet. 

 Unfortunately, when I had time to go to the Bodleian Library to 

 try to identify the creature, and found it was not in Saville Kent's 

 book, I could no longer get any specimens. I have searched for 

 them this spring, but a bridge is being built near the ditch, and I 

 fear they have been destroyed. 



If it should be decided that this is a new species, I would 

 suggest the name " raptor,"" but if there is no genus in which it 

 can be placed, I would call it li Ilarpakter socialist from " ap^a^ou," 

 / snatch, which would at once identify it among the Flagellata 

 eustomata, from its method of seizing its prey. 



