140 H. W. KING ON FOND LIFE FROM THE WEST INDIES. 



back, with two short horn-like processes at each side, capable 

 of slight contraction and extension. It has one ruby-coloured 

 eye, situated upon a stylif orm process of the head. The outlines of 

 the trunk follow nearly horizontally from the head to about three- 

 fourths of the length of the animal, where the body is suddenly 

 reduced in size, as each successive ring of the integument 

 becomes smaller than the preceding, this annulous formation 

 enabling the animal to curve and bend in any direction, as each 

 larger ring of its structure works over the smaller. The tail 

 bifurcates from the end of the body, is telescopic, and ends in 

 two powerfully-formed, articulated, toothed claws, curved in 

 outline, and very useful to the animal's mode of life. The 

 animal can at will close the two bifurcating branches of the 

 tail, with the claws attached, so that they lay in the same line 

 but with a downward curve, as in Fig. 2, PI. VIII. Or it may 

 spread them rigid, as in Fig. 1, PI. VIII., with the clawlets of 

 the claws elevated or depressed, according to the requirements 

 of the animal. This control over the clawlets is a very im- 

 portant one to this Rotifer, enabling it to use each claw of the 

 tail as a simple tool by thrusting it into substances without the 

 clawlets forming an obstruction, which they would do if they 

 were fixed and always erect. Again, they are useful as a com- 

 pound tool when they are elevated, by forming a notched hook, 

 stronger and better adapted for loosening materials, and also, 

 as in Fig. 5, PI. VIII., for drawing earthy particles to their 

 tubular dwellings, which they could not so well do if each claw 

 was a plain, smooth hook. 



They live almost entirely in either appropriated tubes formed 

 by the hollow stems of aquatic plants, or burrowings of the 

 worms aforesaid, or tubes constructed by themselves from the 

 flocculent sediment at the bottom of the water. When forming 

 a tube, it is interesting to notice how the animal forces its head 

 into the decaying vegetable matter or refuse, and having made 

 a hollow about half the length of the creature, and as if the 

 matter would not yield further by this mode, it turns round, 

 with its tail in the burrow and the head outside. Then, fixing 

 its notched tail, over which it has considerable control, in either 

 side of the burrow, it moves backwards and forwards, loosening 

 the materials as it does so, and gradually forcing its way in, at 

 the same time pressing the aides outwards suflficiently to enable 



