CHIBONOMID/E. 



waters^ and keeps its body always doubled, as it were, in two, 

 against the sides of ditches or the stalks of aquatic plants. If it 

 is placed in a glass half-full of water, it so fixes itself against the 

 sides of it, that its head and tail are in the water, Mdiile the re- 

 mainder of the body is out of it, thus assuming the form of a 

 siphon, the tail end being the longest. When it is disposed to 

 feed, it lifts its head and places it horizontally on the surface of 

 the water, so that it forms a right angle with the rest of the body, 

 which always remains in a situation perpendicular to the surface. 

 It then agitates, with vivacity, a couple of brushes, formed of hairs, 

 and fixed in the anterior part of the head, which producing a cur- 

 rent towards the mouth, it makes its meal of the various species 

 of animalcula, abounding in stagnant waters, that come within 

 the vortex thus produced. As it requires to be firmly fixed to the 

 substance on which it takes its station, and its back is the only 

 part, when it is doubled, that can apply to it, it is furnished with 

 minute legs armed with black claws, by which it is enabled to 

 adhere to it. It has ten of these legs : the four anterior ones, 

 which point towards the head, and are distant from each other, 

 are placed upon the fourth and fifth dorsal segments of tlie body ; 

 and the six posterior ones, whicli point to the anus, and are so 

 near to each other as at first to look like one leg, are placed on 

 the eighth, ninth, and tenth. When the animal moves, the body 

 continues bent, and the sixth segment, which is without feet, and 

 forms the summit of the curve, goes first. Its legs are of a nearly 

 similar construction with those of HelojjJiilus ])enclulus. In the 

 interior of its thorax are two long, oval, opaque bodies, which are 

 supposed to be air-reservoirs ; these, when the animal assumes the 

 pupa, a|ipear to become external, and are placed on the back, 

 precisely where the respiratory horns of aquatic pupae are usually 

 situated, and apparently terminate in a transparent point. The 

 pupa is bent, like that of Culex, but with broader oval thoracic 

 appendages, and small anal plates. 



"The larva of T. monllls is found in swampy places and in 

 ditches, is not bigger than a horsehair, and about a quarter of an 

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

 with an undulating motion of the body, and it sometimes walks 

 upon the bottom of tlie water and upon aquatic plants. It has 

 three legs; the anterior leg is attached to the imder side, towards 

 the head, of the first segment of the body; it is long and cylin- 

 drical, placed perpciuliculariy or oblicjuely, according to the difierent 

 movements the animal gives it, and terminates in two feet, armed 

 at their extremity by a coi'onet of long movable hooks ; these feet 



