INTRODUCTION. 6 



possible referenre elsewhere has been su<;<,r('stetl, tliis stiororfstioii will Imrrlly 

 stand the test of investig'atioii, ami the matter remains wlicn- I left it; and 

 in the present work attention is directed to another yroup — the ( 'oleopterons 

 tamih K'ln ncliitida — in wliicli it has been fonml niMi-ssary to establish a 

 new siibtaniilv ^roiip tor an abundiinl and varied scries ot" insects trom our 

 Tertiaries. 



In stndyino- the Hliyn(lioj)horons ( 'oleoptera, 1 have, for the first time, 

 made use of all the material which has l)ecn collecte<l in the most recent 

 as well as in former yenrs; and have been able, therefore, to do justice to 

 the other localities of fossil insects, as well as the now fanions locality of 

 Florissant, Colorado, ami 1 tind tliat there is no family oi' American Rhyn- 

 cliophora paleontologically more interesting than the Rhynchitida?. In point 

 ot' numbers alone the species of this group form more than 10 per cent of 

 tlie fossil Hhynchophora of North America, while in the existing fauna the 

 Hhvnchitidpp comprise less than 2i per cent of all the Rhyn«'liophora. Our 

 recent Rhynchitida- are separated by IjC Conte and Horninto two subfamilies, 

 one of which comprises the bulk of the family, wdiile a single species is sepa- 

 rated to form the other, the Pterocolinaj. This differs from the Rhyiichitina% 

 among other things, by the antennae being inserted much nearer the eyes, 

 by the wide separati<in of the fore and middle coxae, and by the broad side 

 pieces of the raetasternum. The PterocoliniB are not represented among 

 the fossils, but all the genera of Rhynchitina^ now existing in our fauna are 

 recognized, as well as a new generic type. These, however, are but a 

 mere fraction of the fossil Rhynchitida% the l)ulk of them being separated 

 as a new sidifamily — the Isotheina', a subfamily characterized by the mod- 

 erate separation of the fore and middle coxaj, and by the insertion of the 

 antennif, which is before the middle of the basal half of the straight and 

 pon-ect beak. These characters show an approach to the I'terocolinai rather 

 than to tlie Rhyn(;hitina', but they have narrow metastenial side pieces. This 

 subfamily, thus clearly distinguished, is, for Rhynchitidsr, exceptioTially rich 

 in forms, since it contains no less than seven genera and thirteen species, 

 about equally diAnded between two distinct tribes, all extinct. This brings 

 the total number of fossil American Rhynchitida; up to four-fifths that of 



