TERTIARY RTTYNCllOPIIOROLTS COLEOPTERA 

 OE THE UiNlTEl) STATES. 



By Samuel H. Scuddek. 



INTRODlJin ION. 



Althoiijjh it is evident to any student <»f" fossil insects tliat even in 

 Ti'i'tiary de})()sits we possess but a mere fragment of" tlic vast Iiost wliicli 

 nuist liave been entombed in tlie rocks, it is nevcrtliclcss true tiiat we iiave 

 already discovered such a variety and al)iuiilance of forms as to make it 

 clear that there has been but little important change in rhe insect fauna 

 of the world since the beginning of the Ti'rtiary ejxxli. In the earlier 

 Tertiaries we not only possess in profusion i-ejjresentatives of every on<^ of 

 tile orilers of insects, but every dominating family ty])e which exists to-day 

 has been recognized in the rocks; even many of tin- families whidi have 

 now but a meager representation have also l)eeii diseovered, ainl tliough 

 manv extinct genera have been recognized, no higher groups, witli a single 

 exception or two, have been founded ujjon extinct forms. This is one of 

 the most striking and prominent facts which confront tlie student of fossil 

 insects. It is the more striking froui the delicacy, the tenuity, and the 

 minuteness of many of the forms which have been entond^ed; and the state- 

 ment ina\ 111' enforced bv the further fact that the parasitic groups — those 

 which are entoiiiophagous — are represente(l, as well as many of those wdiicii 

 in tti«! piesi'iit time show peculiar modes of life. Thus we have rejiresenta- 

 tives of sucli microscopic parasitic in.sects as Myrmar, strepsipterous in.sects 

 have been discovered, the viviparity of the ancient Aphida- has been shown 

 probable, the s|)ecial sexmd forms of ants and white ants were as clearly 



.MON XXI 1 



