REPORT OF TEE CHIEF ASTRONOMER 823 



SESSIONAL PAPER No. 25a 



horizons, and their appearance and mode of occurrence accords best with the 

 hypothesis that of these two they represent the lower or Coldwater horizon, but 

 for the present this correlation stands merely as a probable conjecture. ' 

 (16: p. 75B.) 



An enumeration of the various types of plants found in the localities indica- 

 ted by the above numbers, gives the following: — 



Taxodium distichum .Leafy branch. 



Cupressoxylon macrocarpoides Wood. 



Picea columbiensis Wood. 



Cyperacites haydenii 



Cyperacites, sp 



Phragmites, sp 



Betula, sp Fruit. 



Ulmus protoracemosa Wood. 



Ulmus protoamericana Wood. 



Ulmus columbiana Wood. 



Ulmus, sp Leaf. 



Potamogeton, sp Fruit and leaves. 



Fern stipes 



Exogenous wood 



Undeterminable fragments of leaves 



Pinus columbiana Wood. 



This flora represents a remarkable preponderance of woods, several of which 

 are entirely new, and in such cases previous knowledge cannot be utilized as 

 an indication of the horizon they represent. There are, nevertheless, certain 

 well defined forms of known value, and these will serve as a means of determin- 

 ing the horizon in connection with the general facies of the entire flora. From 

 the list, we may nevertheless exclude the fern stipes, the exogenous wood and 

 the undeterminable leaves as throwing no light whatever upon the problems 

 before us. 



The genus Picea, although somewhat sparingly known in the fossil state, 

 is. nevertheless, found to be distributed through a rather wide range of horizons. 

 It is a well recognized and rather abundant element of the Pleistocene flora, 

 in which several existing species are represented by both wood and leaves (48), 

 Similarly also, Knowlton (38 : p. 215) has shown that existing species are still 

 undergoing deposition wherever local glaciation is in progress. Picea quilchen- 

 ensis, Penh., has been recognized somewhat recently in the Oligocene of the 

 Quilehena basin, British Columbia (1), but as the plant is represented solely 

 by its leaves, it is impossible to determine its precise relation to other fossil 

 forms, although the character of the foliage offers a suggestion that it may be 

 related to the existing P. breweriana or P. sitchensis. More recently, Berry 

 (3) has determined the extension of the genus into the Upper Cretaceous forma- 

 tion of New Jersey. In the Cliffwood clays he has found beautifully preserved 

 cones which he regards as representing a species comparable with the existing 

 P. excelsa. 



