THE FIFTH FAMILY 



PENTAiMEROUS COLEOPTERA. 



Palpicobnes 



Present us, like the preceding, with antennae terminating in 

 a knob, and usually perfoliate, but with nine articulations 

 at the most in all, inserted on the lateral and advanced edges 

 of the head, but little longer than it and the maxillary 

 palpi, and often even shorter than these latter organs. The 

 chin is large and buckler-formed. 



The body is, in general, ovoid, or hemispherical, gibbous, 

 or arched. The feet are in many adapted for swimming, 

 and have then but four or five very distinct articulations, 

 but the first of which is much shorter than the following ; all 

 the articulations are entire. 



Those whose feet are proper for swimming, with the first 

 articulation of the tarsi much shorter than the following, 

 and whose joints are entirely corneous, will compose a first 

 tribe, that of hydrophili, which embrace the genus 



Hydrophilus of GeoiFroy. 



Linnaeus has formed of it but a single division (the first) 

 of his genus Dytiscns ; but the anatomy of these insects 

 differs essentially. The digestive canal of the hydrophili 

 has much analogy from its length, exceeding four or five 



