524 



FLOKA OF THE LAIIAMIF, CIJOFP. 



systematic order in two opposing columns, with the number of species 

 belonging to each : 



Laramie and Seuouian. 



Genera. 



Zamiostrobus 



Abietites 



Taxites 



Sequoia 



Taxodium . . . 

 Phragmites.. 



Populiis 



Juglans 



Platanus 



Cornus 



Acer 



Rhamuus 



Paliurus 



Fraxiuus 



Viburnum . . . 



Laramie and Eocene. 



Genera. 



Halymenites 

 Cauliuites ... 



Sabal 



Flabellaria . . 



Alnus 



Rhus 



Sapindus 



Vitis(?) 



Zizyphus 



Celastrinites 

 Grewiopsis... 

 Dom bey opsis 

 Magnolia ... 



4 

 6 

 9 

 4 

 6 

 9 

 5 

 3 

 8 

 4 

 6 

 14 

 9 



We thus have fifteen genera belonging to the first class and thirteen 

 to the second. Both lists would admit of reduction, but some good 

 reason can be urged in each case for retaining it. 



We may examine these several characteristic genera somewhat in 

 detail. Beginning with the first list we find a single species of Zami- 

 ostrobus iH the Laramie and in the Senonian. The latter occurs in the 

 Gosau formation at St. Wolfgang, Austria, the geological position of 

 ■which is now believed to be definitely settled as upper Cretaceous. The 

 Laramie plant is of a somewhat doubtful character, but is clearly cyca- 

 daceous. It was found at Golden, Colorado, lying on the surface in 

 the vicinity of Laramie beds, and is believed to belong to that formation. 

 The genus, like all fossil cycadaceous genera, is strongly Mesozoic, being 

 found as low as the Oolite. 



Abietites, two species of which occur in the Laramie, one being found 

 in both the lower and the upper district, is one of the most ancient of 

 the typical coniferous forms, being found all the way from the Wealden 

 to the Miocene, except in the Eocene, wliere it is thus far absent. The 

 only Senonian species comes from the Harz district. 



The form distinguished as Taxites seems to belong to the northern 

 portion of the western hemisphere, the two Laramie species being re- 

 ported from British America, and the Senonian species from the beds of 

 Patoot, Greenland. A true Taxus occurs in the Loudon clay, and this 

 seems to be a geographical variety. 



