254 THE BRITISH NATURALIST. [Novbmbfr 



and disposed in a similar manner with regard to the sixth ring, 

 consequently they can all concur in advancing this ring to a certain 

 point, as the legs of other animals advance their heads. In short, it is 

 easy to see how these legs, whose extremities are turned to the head 

 or the tail of the worm, serve to move it. It has only to carry its legs 

 backwards or towards the middle ring and it will walk directly. But if 

 it wishes to go backwards or to make its head and tail go first, its legs 

 cannot serve it. To move itself in this way it has only its vermicular 

 movement, made use of much more rarely and with much greater 

 difficulty than the other. Besides the movements of which we have 

 spoken, this worm can execute two others by means of its legs. It can 

 move sideways, because its legs are not only movable from front to 

 back but from right to left and from left to right. Sometimes it makes 

 use of this movement when it wishes to go only a very short distance, 

 moving parallel to its doubled-up parts. When entirely plunged into 

 water it extends itself its full length and swims like other worms. 

 After all, it appears to me that it never goes into open water unless 

 compelled, and then always regains its bank as soon as possible, and 

 places itself with its mouth turned upwards. The mouth is surrounded 

 by four little tusks or hooks like the mouths of voracious insects. From 

 the middle come two other parts like tufts. The animal is continually 

 agitating these little tufts. It lengthens and retracts them, moves them 

 from right to left. This little agitation keeps the water moving. It 

 even seems to draw the water a little, as if the insect were breathing. 

 What is certain is that while it is quickly moving these little tufts the 

 tiny creatures that swim in the water near enough are drawn near the 

 mouth and dexterously captured. As soon as some little creature is 

 drawn near enough the insect advances its head and greedily seizes it 

 and swallows it. In this manner I have seen it capture insects so 

 small that they could not be perceived without the aid of a good glass. 

 Though its prey is so small it eats a good deal in proportion to its size, 

 for it is continually taking these tiny creatures into its mouth." 



If our readers will now turn to the illustration of Dixa (Plate XL) 

 which Mr. Hammond, F.L.S., has kindly drawn from the best of my 

 mounted specimens, they will see from the position of the head, appar- 

 ently turned quite round, how easy it was for the old French naturalist 

 to mistake the dorsal for the ventral side. The larva is of a very 

 dark brown colour, the setae and bristles being almost black, the head 

 itself and the tusks being of a much lighter brown. The long setae on 

 the first segment next to the head and the last four segments are very 

 noticeable. Mark, this is the appearance of the larva as it swims 

 through the water, or at all events as the spirits of wine killed it in all 

 the three specimens mounted. It was quite impossible to say how its 

 head was fixed when I had it in the zoophyte trough and forced it down 



