190 Transactions of the [''.Z^l 5[K« 



young one either come from behind, or else out of a tube inhabited 

 by an old sj)ecimen. It swam away so fast that I had not the power 

 of making a sketch of it. It was like a small stentor or a young 

 tubicularia. I have comjjared it to these two, for the stentor, when 

 free swimming, takes so many forms. 



My reasons for thinking the above animal is a stentor is its 

 general configuration, its having no trace of an alimentary canal, 

 and the total absence of a masticatory apparatus, there being not 

 any division in the body hke there is in all the rotatoria, between 

 body and foot stalk, and its being filled with a granular sarcode, 

 containing vacuoles, like all the family of Vorticelhua. The only 

 difficulty in the matter is, that, as a stentor, it ought to be clothed 

 with cilia, which these long hairs on this animal can hardly re- 

 present, for they are not thickly placed, they stand erect and at a 

 distance fi'om each other ; and they are not vibrating. It is different 

 to the Stentor MuUeri in many ways : besides the absence of cilia over 

 the body, the disc is carried by this creature in a more erect posi- 

 tion, perpendicular to the body, whilst in S. Mulleri it is horizontal 

 to it, and the shape of the expanded disc is very diff'erent. The 

 tube is in this creature a well-made, regular tube, and is opaque 

 when old. In S. MuUeri it is floculent and transparent even when 

 stained with the foecal discharges of the animal. That this animal 

 is not a wanderer that has taken possession of the case of another 

 animal is shown by their being social in their habits, and it would 

 be extraordinary that they should find a colony of tubes ready for 

 them when required. Then, again, the case is well made and fits 

 its possessor, which would not be the case if it were borrowed. 



I have found this animalcule for three years in the same place, 

 from the end of summer to as long as any weed lasts in the river at 

 that place. It is on the north side of a wall built into the river 

 Thames, overhung by elms, therefore it is always in the shade. 

 This is just above Moulsford Ferry. They are always the same, 

 showing them to be, I think, animals sui generis. I will draw the 

 distinctive characters up as follows : — 



The animal lives attached by the lower portion of its body 

 within a tubular case, which is firm, of a light brown colour when 

 young, shghtly transparent, becoming opaque and of a darker colour 

 with age. The animal is trumpet-shaped when extended, ovoid 

 when contracted. The body is covered with long hairs, standing 

 erect from it, and continued round the expanded head, on a plane, 

 external to the cilia, which are placed on the free edge of the velum, 

 which runs round within the edge of the ear-shaped disc. Where the 

 perpendicidar portion is joined by the lower portion on the left side 

 two ciliated processes are sent to the centre of the head, and between 

 these the mouth, which is funnel-shaped, is placed, and I think the 

 anal opening. The mouth is lined with vibrating cilia, and leads down 



