OF THE ORDER COLEOPTERA. 283 



rendered more fit to resist the water, and cause the body to 

 advance. 



This larva appears at once to perceive the smallest insect 

 which moves in the water, and never fails to pursue it on 

 the instant, and seize it with its teeth. These teeth, two in 

 number, are attached in front, on each side of the head. 

 They are curved, and meet each other when the larva keeps 

 them in a state of repose. They have no denticulations, but 

 diminish by little and little into a point. Swammerdam has 

 mentioned that the teeth of the larvae of this genus have an 

 aperture in the form of a cleft near their point, and that it is 

 by this aperture that they suck the insects, the fluid sub- 

 stance of which passes from there into their mouth and 

 stomach. It is known that the antlion sucks in insects in 

 the same manner. Degeer, in confirming the observations 

 of Swammerdam, has thought that the larva has also a 

 second mouth, and that this mouth was placed between the 

 two lips. What appears to prove this is, that he has seen a 

 larva not only suck in an aquatic wood-louse, but also devour 

 by little and little, all the solid parts of that insect ; which 

 assuredly could not have passed through the little apertures 

 of the teeth. Two muscles have been remarked, divided 

 into many flat and fibrous ramifications. One is attached to 

 the external side of the tooth, and serves to draw it away 

 from the head. The other is attached to the interior edge of 

 the tooth, and it is by this muscle, that the insect draws it 

 close to the head, when it has seized its prey. The head is 

 furnislied with two small antennae placed immediately in 

 front of the eyes. 



These larvge are exceedingly voracious. With their large 

 teeth they seize all the insects which they meet, to suck and 

 devour them, and especially the larvae of the libellulse, 

 ephemera, tipulae, &c. 



It is not rare to find these larvae in all the dormant waters 



