ORDER COLEOPTERA. 425 



times that of the body, and from its contexture, to that of 

 the lamellicornes, and does not approach to that of the 

 carnivorous coleoptera, but in the relation of the biliary 

 vessels. They have neither the natatory bladder, nor the 

 excrementitious apparatus, which characterizes the hydro- 

 can thari. In the females alone, this apparatus is replaced 

 by the organs secreting the matter, which is proper to form 

 the cocoon which encloses the eggs, and the anus presents, 

 for this effect, two filaments. In fine, the masculine genital 

 organs have the greatest relations with those of the coleop- 

 tera of the preceding family.* 



Some, whose body is sometimes oval, oblong and de- 

 pressed, or elongated and narrow, with the corslet uneven, 

 and contracted posteriorly, the legs slender, furnished with 

 small spurs, and the tarsi filiform, little or feebly ciliate, 

 and terminated by two strong crooks, have antennas (always 

 composed of nine articulations,) finishing in a knob, almost 

 in the form of an inverted cone, slightly perfoliate, or 

 almost solid, and the extremity of the mandibles entire or 

 terminated by a single tooth. These palpicornes are all very 

 small, swim little or badly, inhabit stagnant waters, and 

 sometimes remove from them, to conceal themselves in the 

 earth, or under stones. They compose the family of the 

 Helophokidea of Dr. Leach, a denomination which re- 

 minds us of the genus Elophorus of Fabricius. 



In some, the length of the maxillary palpi does not 

 exceed that of the antennae, or is even inferior to it. The 

 chaperon is entire, or without any remarkable emargination . 



Sometimes the maxillary palpi are terminated by an arti- 

 culation which is thicker and ovaliform. 



* " The conformation and structure of the male genital organs of the 

 palpicornes fully justify the place which M. Latreille has assigned 

 them in the entomological scale." (Leon. Dufour, Ann. des Sc. Nat. VI. 

 p. 172.) 



