746 Mr. Gilbert J. Arrow on 



placed between the Hybosoridse and Aphodiida?. The last 

 three genera, however, he placed in closer relation to each 

 other than to the first, whose various peculiarities of 

 structure give it an isolation which the discovery of the 

 stridulating apparatus of all the genera makes still more 

 conspicuous. This apparatus is exactly analogous in all 

 the other genera and absolutely different to that found in 

 Ochodxus. The similar discovery in Taurocerastes and 

 FricJdus tends to justify the otherwise unnecessary 

 creation by Germain of a separate family (Taurocerastidse) 

 for those two genera, while the new genus Tdiostoma just 

 described has at least an equal claim to family rank. Un- 

 fortunately the larvEe of all these interesting forms, which 

 should throw valuable light upon the degree of their 

 relationships to each other and to other Lamellicorns, are 

 entirely unknown. All the genera, however, seem to me 

 to have closer relationships with the Geotrupida' than with 

 any other family, and the alternatives which present them- 

 selves to me are either still further to multiply the family 

 divisions in order to retain those now in existence, or by 

 somewhat extending the definition of the Geotrupidse to 

 include all in a single family and regard the various 

 divisions as sub-families only. In the absence of full data 

 to justify the former course and in view of the differing 

 conceptions of entomologists as to the proper value to be 

 assigned to a " family " in the Coleoptera, it seems to me 

 desirable rather to reduce than multiply such groups 

 where common characters exist, and in the present 

 instance I believe that a greater degree of uniformity 

 will be introduced among the families of Lamellicornia 

 by regarding the small groups here dealt with as com- 

 prehended in a single family. 



The Aphodiidse and Hybosoridse seem to be entirely 

 without stridulating organs in the adult form, while those 

 of the larval Aphodiidse seem to associate them with the 

 Copridge. The Hybosoridfe are rather doubtfully homo- 

 geneous, but have probably nearer relationships to the 

 Trogidas and Giaphyridse than to the groups now under 

 consideration. 



Practically the only characteristic distinguishing the 

 Geotrupidse as hitherto restricted is the possession of eleven 

 joints in the antennae, a feature which, although excep- 

 tional and important as evidence of the primitivenessof the 

 group, cannot be regarded, in view of the variation in the 



