266 C. F. ROUSSELET ON BATTOLCS COLLARIS. 



Collins has even sent me some copies of his original sketches, 

 including a transverse section, which shows that he, at the 

 time, understood the lorica quite correctly, and it is surprising 

 that Mr. Gosse, with this 6gure to guide him, interpreted it 

 differently. It is necessary to point out all these facts to 

 prevent further misunderstanding, and I shall place a mounted 

 slide of this Rotifer in the cabinet of the Club for reference. 

 Rattulus OoUaris, sp. n. (Fig. 1). 



In the Sandhurst ponds I also found a new Rattulus which 

 I have named B. Oollaris, and which forms the principal sub- 

 ject of this paper. 



In shape the body is roughly cylindric, slightly curved behind ; 

 the lorica is finely pitted or stippled, giving it a roughened ap- 

 pearance; it lias no dorsal ridge and is fairly stiff except m 

 the neck region, where the integument is more flexible and 

 frequently forms a thickened collar when the animal i> bending 

 or retracting, and from this characteristic peculiarity the animal 

 derives its specific name. The foot opening is oblique, nearly 

 ventral, and the lorica overhangs the foot dorsally in a marked 

 decree. The head is elongated, truncate in front, and somewhat 

 tapering anteriorly, and it is furnished with a simple wreath of 

 cilia; it contains a conical brain mass with a red eye at the 

 tip and a large mastax with long jaws of the Rattulus type 

 The Ion- thin oesophagus is attached to the anteno-dorsal part 

 of the mastax and widens into the large saccate stomach and 

 intestine. Rounded gastric glands are attached to the anterior 

 part of the stomach in the usual way. The ovary is an oval 

 'late with large nuclei imbedded in its granular substance, 

 and it has generally a large maturing egg attached to it, 

 Lateral canals, with flame cells attached, and a contractile 

 vesicle are present. The dorsal antenna emerges from a small 

 depression in the head, just behind the tip of the brain, and the 

 lateral antenna, are situated in the lumbar region, on each side 

 of the body. The foot emerges nearly ventrally ; it consists ot 

 two short joints and is furnished with two very long, thm, narrow, 

 classv toes, about half the size of the body in length. The toes 

 are nearly straight for about half their length, then they arc 

 deonrredj one, or two, very small substyles are present at 

 the base of each toe. 



