278 MOTIONS OF INSECTS. 



to the fly), have each a fleshy leg on the underside of 

 the first segment, which points towards the head and 

 assists them in their motions*. — Others again go a little 

 further, and are supported at their anterior extremity 

 by a pair of spurious legs. An aquatic larva of a most 

 singular form, and of the same tribe, figured by Reau- 

 mur, is thus circumstanced. In this case the processes 

 in question proceed from the head, and are armed with 

 claws'*. Would you think it — another Tipulidan grub 

 is distinguished by three legs of this kind ? It was first 

 noticed by De Geer under the name of Tipula mcicidata 

 {Tanypus^ Meig.), who gives the following account of 

 its motions and their organs : — It is found, he observes, 

 in the water of swampy places and in ditches, is not 

 bigger than a horse-hair, and about a quarter of an 

 inch in length. Its mode of swimming is like that of a 

 serpent, with an unduhiting motion of the body, and it 

 sometimes walks at the bottom of the water and upon 

 aquatic plants. The most remarkable part of it are 

 its legs, called by Latreille, but it should seem impro- 

 perly, tentacula. They resemble, by their length and 

 rigidity, wooden legs. The anterior leg is attached to 

 the underside, but towards the head, of the first seg- 

 ment of the body. It is long and cylindrical, placed 

 perpendicularly or obliquely, according to the different 

 movements the animal gives it, and terminates in two 

 feet, armed at their extremity by a coronet of long move- 

 able hooks. These feet, like the tentacula of snails, are 

 retractile within the leg, and even within the body, 

 so that only a little stump, as it were, remains with- 



^ De Geer, vi. /. xxii. f. 15,2. I. xviii. f. 8, p. 

 " Reaiira. v, t. vi. f. 5, mm. 



