834 DEPARTMENT OF THE INTERIOR 



2 GEORGE V., A. 1912 



The Miocene age of the Similkameen beds has been adopted by Ami (2: 

 iv., 220), who includes them in the Cordilleran Region, basing his opinion upon 

 the determinations of plants by Sir William Dawson, and of insects by Scudder 

 (1: p. 7). Ori the other hand, Dr. G. M. Dawson, in adopting the view that 

 the Similkameen beds are Oligocene or later Eocene (16: pp. 75-76 B), bases 

 his opinion upon the results obtained by Scudder, according to which sixteen 

 out of nineteen species of Tertiary Hemiptera were from the Similkameen beds 

 — all but one being new — and in their general facies of the Oligocene type, 

 although the general fauna showed definite relations with the Middle Miocene; 

 while Cope recognized the remains of Amyzon in the Similkameen beds which 

 were, therefore, regarded by him as equivalent to the Amyzon beds of Oregon, 

 and hence of Oligocene age. Dr. Dawson further observes that ' It is probable 

 that the Similkameen beds may . . . represent the Coldwater horizon, but 

 for the present this correlation stands merely as a probable conjecture' (I.e.). 

 According to this hypothesis, the Coldwater horizon is within the Oligocene 

 formation, and this conclusion is in exact accordance with the results of our 

 present studies. Reference to the accompanying table will show that out of 

 thirty species from the Similkameen beds, only ten, or 33 per cent, are Lower 

 Eocene, thus leaving two-thirds as distinctly Upper Eocene and with Miocene 

 affinities. From these considerations it would seem altogether probable that 

 we must hereafter regard the Similkameen beds as Oligocene, and to the same 

 category must no doubt be referred the various deposits at Midway on the Kettle 

 river, where, out of seven identical species, three are distinctly allied to the 

 Similkameen, and one to the Green River group, thus giving 57 per cent of 

 Upper Eocene types. With respect to the plants from the Horse-Fly river at 

 Cariboo, it should be pointed out that the number of species is small, and that 

 they do not afford a fair opportunity for final judgment, but within the limits 

 of twelve; species four are definitely Upper Eocene, six are as definitely Lower 

 Eocene and two are common to both horizons, while four species establish a 

 strong contact with the Cretaceous ; but as Taxodium distichum is a very cosmo- 

 politan species of wide range, it cannot be said to have leading weight in a 

 question of this kind, more especially as its chief aspect is Eocene. Alnites 

 grandifolium is common to the entire Eocene, being found in the Red Deer River 

 group as well as in the Similkameen, so that it affords no conclusive evidence 

 as to the relative age of the beds in which it occurs. Whether Alnites and 

 Taxodium be excluded or not, the general facies of the Horse-Fly river plants 

 inclines much more to the Similkameen group than to the Fort Union or the 

 Red Deer river, and our opinion is that they distinctly belong to the Oligocene. 



The specimens from Coutlee, B.C., are but three in number, and they are 

 altogether too inadequate to base an opinion upon. One species — Taxodium 

 distichum — may indicate anything from Lower Eocene to Miocene. Ficus, 

 represented by an undescribed species, may also indicate any horizon within 

 the Eocene. The only genus of value in this respect is Ulmus, which suggests 

 Upper rather than Lower Eocene, and it is thus quite possible that the Coal 

 Gully deposits may be of Oligocene age, as suggested by Dr. Ami (1: p. 8). 



