Sound-production in the Lamellicom Beetles. 749 



the organs of the mouth, with the broad extruded hbrum 

 and mandibles, are common to the two groups. Again, 

 the larvse of the Lamellicornia are in general more or less 

 closely hairy and the anal 0}Dening is simply transverse and 

 exactly terminal. Those of both Geotrupidae and Passalidas, 

 on the contrary, are smooth, and in both a pair of lateral 

 lobes appears by which the anal orifice is confined so as to 

 assume a somewhat stellate form. In the Lucanidse it is 

 again quite different, being longitudinal, and this family, 

 besides many other peculiarities, is distinguished from 

 other Lamellicorns by a much less concentrated nervous 

 system. 



The arrangement of Lamellicornia as Passalidge, 

 Lucanidge and Scarabseidse, therefore, does not seem to 

 me to correspond with our present knowledge of the facts. 

 The first family, which is one of the most homogeneous 

 among beetles, must be closely associated with the third, 

 which is by no means homogeneous and consists of an 

 assemblage of families ; Avhile I regard the Lucanidae as 

 the extreme branch of the Lamellicorn series, having only 

 very slight affinities with the Passalidse, which may be 

 due more to similarity in their mode of life than to any 

 fundamental relationship. 



List of Stridulating Genera of Lamellicorn Beetles. 



Genera only known to stridulate in the larval stage are 

 not included in this list, as our knowledge of these has 

 not materially increased since the work of Schiodte in 

 1874. The very numerous genera of Passalid^, in which 

 stridulation is general, are not separately enumerated. 



PAOE PAGE 



Ischiopsoplia 715 Golofa 720 



Macraspis 712 



Lagochile 714 



Geniates ih. 



Serica 715 



Heteronyclius 718 



Pentodontoschema . . . 719 



Callistemonus ib. 



Podalgiis ih. 



Orator ih. 



Pimelopus ih. 



Xenodorus ih. 



Thronistes 718 



Scaptophilus 717 



Corynosceli-; 718 



Mellissius ib. 



Acerus 719 



Loncliotus 718 



Camelonotus 717 



Dipelicus 718 



Augosoma ih. 



Oiyctes 716 



Trichogomphus .... ih. 



