6 TERTIARY RHYNCHOrilOROUS (XJLEOPTERA. 



divided between those wliicli are predominantly North American and those 

 which are tropical American, but often extend to our soutliern l)orders. Of 

 the 31 new g-enera (with 57 species) little can be said in this })articular, but 

 nearly half of tlu^m may be i-eg-arded as most closely allied to American and 

 especially tropical American types; so that on the whole the American, and 

 especialh' the tro])ical American, ty{)e jjredominates. It should be remarked, 

 however, that the n-scinldaiicc of the fauna to that of temperate North 

 America is uiidoiibtedh' greater in ap})earance than in reality and will ver}" 

 probably be changed to some extent when the various species here recorded 

 are better known; for, in default of characters which if preserved might 

 materially change tlie alleged atHnities of the various forms, it has seemed 

 advisable to refer most of them to existing genera, and my opportunities for 

 examining tro|)ical ami suljtropical ty])es have been very limited. Where 

 characters of real importance exist, the insects generally show the preva- 

 lence of structural differences, often considerable, from modern forms. 



The number of new genera here propos(ul is certainly greater than has 

 been usual in the study of Tertiary insects, but this I believe to be a neces- 

 sity if we are to tipidy the same methods to their studv that we do to the 

 study of modern insects; nor is the number surprising, since not a single 

 species is found in oin- T(-rtiary deposits which can possibl}' be referred to 

 an existiuii' form or even to any of those which have been described from 

 the European Tertiary rocks; and 1 am convinced that the actual difference 

 between the older Tertiary and existing types is far better expressed by the 

 separation of the former from the latter in generic nomenclature whenever, 

 the characteristics l»eing .sufficiently preserved, they show any such differ- 

 ences as among modern tvpes are regarded as warranting" generic separation. 

 It must be confessed, however, that among the fos.sils the (^oleoptera are 

 far less apt to lia.ve those characteristics of tiieir structure wliich are seized 

 upon for generic disassociation sufficiently jjrtserved to warrant great cer- 

 taint\' or insure exactitude and that those orders whicli disjjlay wing neu- 

 ration afford far better means of judgment, on account of the commonly 

 better preserved remains of just those parts which are largel}' relied upon 

 for generic disci'imination. 



The localities at wliich the species described below have been ob- 



