80 THE CLASS OF INSECTS. 



158 ; those that fire oonimon to l)oth liemispheres forming then 

 more than two-thirds of tlie whole number, while of the actual 

 Coleopterous launa of Europe, according to the calculation of 

 M. Lacordaire, there is only one-third. The genera found to-day 

 in both parts of the Avorld have then during the Tertiary- epoch 

 played a more important part than is the case now ; hence 

 the knowledge of the character of the fauna is rendered more 

 difficult. AVe find at QMiingen but a very small number (five) 

 of genera exclusively European ; seventeen are found to-day 

 in Europe, in Asia, and in Africa, but not in America. For the 

 most part they belong to the Mediterranean fauna (comprising 

 eight genera) and give to the insect-fauna of Q^ningen a strong- 

 proportion of Mediterranean forms. In this fauna I only know 

 of one exclusively Asiatic genus ; tw^o are peculiar to Africa, 

 and two others {Anojylites and Nrnvpactiis) are American. 



"There are now living, hoAvever, in Europe certain genera 

 which, W'ithout being exclusively American, since they are found 

 in Asia and in Africa, belong more peculiarly to America ; such 

 are BeJostomum, Ilyiiselonotas, Diplonychus, Evagorns, Sten- 

 ojwda, Plecia, Caryborus, and Dineutes. . . . The genera i^eculiar 

 to our fauna of Tertiary insects amoinit to forty-four, of which 

 twenty-one belong to the Coleoptera ; among the Orthoptera 

 there is one, and six H^-menoptera, six Diptera, and eleven 

 Hemiptera. They comprise 140 species." (Heer.) 



An ai)parently still richer locality for Tertiary insects has 

 l)een discovered by Professor Denton west of the Rocky j\Ioun- 

 tains, near the junction of the White and Green Rivers, C'olo- 

 rado. According to Mr. Scudder "between sixty and seventy 

 species of insects were brought home, representing nearly all 

 the different suborders ; about two-thirds of the species were 

 Flies, — some of them the perfect insect, others the maggot-like 

 larvje, — but, in no instance, did both imago and larva of the 

 same insect occur. The greater part of the beetles were quite 

 small ; there were three or four kinds of Homoptera (allied to 

 the tree-hoppers), Ants of two different genera, and a poorl}' 

 preserved Moth. Perhaps a minute Thrips, belonging to a 

 group Which has never been found fossil in any part of the 

 world, is of the greatest interest." 



He thus sums up what is knoA>-n of American fossil insects. 



