NEW AND RARE ROTIFERS FROM FORFARSHIRE 243 



expanded. They are broad ovate arms, somewhat expanded 

 at the ends, and, when fully extended, distinctly longer than 

 the breadth of the head. They are furnished with rather 

 long cilia, which cover their ends, and apparently their upper 

 surfaces to the base ; but as the animal swims with great 

 rapidity when they are expanded, the exact distribution of 

 the cilia is difficult to see. How these auricles are projected 

 and retracted, and whether or not they are invaginated into 

 pouches, I have not been able to determine. In their re- 

 tracted state I have failed to see a trace of them. Sometimes 

 a single auricle is expanded alone. On the dorsal side of 

 the head is a short ANTENNA, broad below, then narrowing 

 suddenly to a blunt point, crowned with a tuft of rather long 

 sensory bristles. At the broadest part of the ventricose body 

 spring two lateral tufts of much longer sensory bristles, in 

 the position in which Gosse figures (Joe. eit.) a pair of single 

 bristles only in C. labiatus, but where a bunch of setae has 

 already been recognised in C. pachyurus (Hudson " Rotifera," 

 App. p. 20, footnote). The TAIL is well marked, short, and 

 transparent. It is narrower near the base than in the middle, 

 where there is formed an abrupt shoulder, succeeded by a 

 straight, blunt, apical portion. The FOOT is rather long, and 

 consists of two joints, carrying a pair of straight pointed toes. 

 A very fine covering of gelatinous mucus clothes the body 

 of the animal, so transparent in its nature as to be scarcely 

 detected save for the presence in it of minute adherent 

 particles. 



From this description of the external view it results that 

 our species resembles the description and figure of Copeus 

 I'Jirenbergii in its general form, the size and position of the 

 auricles, the size and shape of the tail, the position of the 

 lumbar processes, and the possession of a gelatinous covering. 

 It differs from the account of that species in not having the 

 tips only of the auricles ciliated (Ehrcnberg's figure suggests 

 an attempt to make the ends of these organs look like the 

 wheels of an ordinary Rotifer), in having only two joints to 

 the foot, but in this matter, though Ehrenbcrg's description 

 gives three, his figure only shows two ; in the possession of 

 two bunches of fine setae in the lumbar region instead of a 

 pair of single stout bristles, a difficult matter to define with 



