WICKHAM: new MIOCENE COLEOPTERA from FLORISSANT. 425 



District of Columbia. It diverges more widely from the percentages 

 shown in Iowa, Indiana, and Colorado, while compared with Alaska 

 and the southern shore of Lake Superior the Chrysomelidae are better 

 represented at Lake Florissant. The Bruchidae show such a marked 

 disparity as to call for instant comment — for while in the modern 

 lists cited they constitute at the most less than ten per cent as great a 

 number of species as the Chrysomelidae, in the Florissant fauna they 

 reach nearly sixty-two per cent. Unfortunately no good or relatively 

 complete lists of all three families exist for localities in the southwestern 

 states, but it is well known that the Bruchidae are more abundantly 

 differentiated specifically in that district. The combined lists of 

 Schaeffer and Snow comprise 24 Bruchidae from Brownsville, Texas, 

 while Schaeffer records 15 species of this family from the Huachuca 

 Mountains of Arizona. In neither locality is there any pronounced 

 poverty of Chrysomelidae, however, so that the relative development 

 of the two families is totally different from that seen at Florissant. It 

 seems that the Bruchidae, like the Rhynchophora, were relatively more 

 abundantly represented by specific forms than was the case with most 

 of our modern families. 



Another striking discrepancy in specific representation is found in 

 the Byrrhidae. Eight species are recognized from Florissant, all of 

 good size and none belonging to the Limnichini. If we exclude Lim- 

 nichus from consideration, none of the recent lists cited contains so 

 many, though we may assume that the faunae of their respective 

 regions are much better known than that of the ancient lake. 



From these considerations, we are justified in believing that the 

 proportional development of the various coleopterous families during 

 the Miocene times differed, sometimes very decidedly, from that ob- 

 taining today. Consequently we should be conservative in using 

 data derived from comparison of these lists with recent ones as bases 

 of conclusions as to probable climatic conditions. 



Regarding the citation of catalogue numbers, I have followed Dr. 

 Scudder's plan of joining by "and" those which belong to a single 

 individual with its counterpart. The drawings of the new species 

 are all made by myself with a camera lucida and are intended to show 

 the form, the outlines of the principal sclerites and the courses of the 

 chief lines of sculpture. Restoration has been avoided. In a few 

 cases, where the members of different sides were unlike through dis- 

 tortion both have been drawn in enlarged detail without special com- 

 ment. 



