
No. 464] STUDY OF THE SALICACEE. , $41 
genus than in the family, and suggests that the former is in 
process of decline, a conclusion which seems to be directly 
opposed by the evidence afforded by the ratio of extinct and 
living forms. Populus gives 18.10%, 43.10 %, and 38.60 % for 
the three horizons with a maximum development in the Middle 
Cretaceous. 
Distribution of Salicace@ in Cretaceous of United States. 
SALIX. 
Lower. Middle. Upper. 
Salix stantoni x 
mattawanensis x 
meekii x 
protefolia x x 
uf exuosa x x 
T lanceo x 
a linearifolia x 
" longifolia x 
cuneata x 
deleta x 
7 x 
inequalis x 
membranacea x 
nervillosa x 
newberryana x 
ciftca x 
purpuroides x 
sp. x 
sp. x 
s$. x 
Sp. x 
Sp. x 
sp. x 
Saliciphyllum ellipticum x 
longifolium x 
garvifolium X mm 
Species 26 11 5 
Percentage distribution 42.3% 46.1%, 19. 2^; 
