Anatomy of the Male Genital Tube in Coleoptera. 623 



Taxonomically this is the simplest of all the series of 

 Coleoptera if we limit it as is here done. 



The structure of Gyrinidae is on a different plan from 

 that of the Caraboidea. When it is remembered in 

 addition to this that all the members of this family are 

 highly specialised for a mode of life that is shared by no 

 other Coleoptera, we are justified in concluding that this 

 has always been an isolated family. 



Cupes aud Omnia do not exhibit any approximation to 

 the Caraboidea of direct nature. 



GICINDELIOAE 



\ 



CARABIDAE \ / DYTISCIDAE 



PAUSSIDAE -X /-PELOBIIDAE 



RHYSOOiDAE \ / — HALIPLIDAE 



FAMILIES OF CARABOIDEA. 



(5) Malacodermoidea. 



In considering this complex we may commence by 

 saying that we have rejected from it various families that 

 were formerly included in it. The Dascillidae are, we 

 consider, nearer to the " simple trilobe " forms we have 

 called Byrrhoidea. The Cyphonidae we are obliged to 

 omit as their aedeagus appears to be very peculiar, and 

 we do not yet understand it. 



This still leaves numerous forms as Malacoderms, As 

 regards some of them taxonomists are not by any means 

 agreed as to their family rank. We take iJrilus as one 

 of the simpler forms. This is a trilobed form modified as 

 to the articulations between the median lobe and the 

 lateral lobes, and between these and the basal-piece. 

 The similarity between this and the more modified 

 Lampyridae is evident. The Lycidae in their simpler 

 forms {Bidyopterus aurora) also approach Drilus, and 

 in more differentiated forms (Lycostomus, etc.) still have 

 the same arrangement, though the median lobe may become 



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