XII 



INSECTS OF THE SEA-SHORE 



377 



be observed. Among the Geodephaga species of 

 Broscus, Callistus, Harpalus, Amara, Calathus, 

 Anchomenus, Clivina, Dyschirius, Chleenius, Ptero- 

 stichus, Stomia, Aepus, Lori- 

 cera, Demetria, and Bembi- 

 dium have the tibial comb 

 in its complete form. All the 

 species which possess it fre- 

 quent moist, dark and dirty 

 places, hiding under stones or 

 logs of wood, burrowing in 

 the earth, or creeping under 

 the decaying bark of trees. 

 The comb on the fore leg of 

 the Honey-bee suggested that 

 the similar structure in Beetles 

 might be employed for the 

 purpose of cleansing the an- 

 tennas from dirt contracted 



in confined situations. To test this, I smeared with 

 gum the antennae of Pterostichus niger, and set 

 the Insect free in a box whose bottom was strewn 

 with fine sawdust. After running wildly about and 

 seeking to escape the Beetle made a careful examina- 

 tion of its prison, waving its antennae, and feeling the 

 ground with them continually. The sawdust soon 

 began to clog the antennae, and then the Beetle would 

 stop, raise its fore leg, bring the antennae into the 

 comb by a movement of the head, and draw it through, 

 thus effectively clearing it of loose particles. One 

 piece of sawdust clung so tight that three distinct 

 pulls were required to remove it. The Beetle then 



FIG. 115. Abdomen of Aepus in 

 outline showing air-sacs in situ. 



