118 



C O N T R I B U T I O N S TO PAL^ONTOLOGY 



age.' Here, then, is an opportunity to see what kind of floral analj^^sis is derived 

 from an assemblage vvhose Montanan age is estabhshed by stratigraphic position 

 and adjacent marine faunas. Such an analysis should prove useful in the correla- 

 tion of other floral assemblages whose age is not so definitely estabhshed. 

 The Ericson-Ahiiond species give the foUowing analysis : 



No outside distribution 14 



Outside distribution 35 (14 in common with type Lance) 



Total number of species ... 49 



Short-ranging species: 



Montanan 11 



Lancian 4 



Paleocene 



15 



Long-ranging species: 



Montanan-Lancian-Paleocene . . 4 



Montanan-Lancian 12 



Lancian-Paleocene 1 (?) 



I7(?) 



Species of uncertain range . . 3 



This summary shows that out of a total of 35 species with outside distribution, 

 14 (40 per cent) are also found in the flora of the type Lance. This is in contrast 

 with the higher percentages seen in floras of known Lancian age and is comparable 

 with the figure for the Vermejo flora. The short-ranging species, however, are 

 overwhelmingly of typical Montanan age, as foUows : 



Montanan age only: 



Ficus regularis 

 Ficus rhamnoides 

 Ficus squarrosa 

 Ficus wardii 

 Grewiopsis cleburni 

 Pterospermites unduiatus 



Lancian age only : 



Cornophyllum wardii 

 Ficus crossii 



Pterospermites wardii 

 Quercus dentonoides 

 Trapa? cuneata 

 Viburnum anomalinervum 

 Widdringtonia? complanata 



Menispermites belli 

 Selaginella? falcata 



The age relations of the liricson-Ahiiond formations to other formations dis- 

 cussed are shown in figure 3. 



Mesaverde flora, southeastern Wyorning — Knowlton has described a number of 

 species coUected from the Mesaverde formation northwest of Laramie, Wyoming.^ 

 This small assemblage gives the foUowing analysis : 



Nooutsidcdistribution 10 



Outsidi; distiibution 1 1 (5 in common witli type Lance) 



Short-ranging species: 



Pre-Montanan 1 



Montanan 



Lancian 2 



Total numl)er of .species 21 



Long-ranging species: 



Pre-Montanan-Montanan ... 2 



Montanan-Lancian 5 



Lancian-Paleocene 



Species of unccrtain range . . 1 



' Stanton, T. W., and Knowlton, F. H., op. cit., 146, 147, 1897. Wilmarth, M. Grace, U. S. Geol. Surv. Bull. 896. 

 1176. 1938. 



« Knowlton, F. H., op. cit., 1-5, 1900. 



