22 THE CANADIAN NATURALIST. [Vol. X 



The fossils of the Lower or Dunvegan sandstones are of 

 special interest, giving us a number of fresh-water mollutcs and 

 land plants of a stage of the Cretaceous previously almost un- 

 represented in these respects. The fresh-water molluscs clearly 

 resemble those of the Laramie group, and the plants, while 

 showing a close analogy with those of the Dakota group, help to 

 fill a gap in time between these and those of the Vancouver 

 (Chico) Cretaceous and the Laramie and Fort Union. 



In 1872, Prof. Meek described a series of beds at Coalville, 

 Utah,* which appear to have been formed at the edge of the 

 Cretaceous sea at the mouth of a small river, and hold fresh- 

 water molluscs. The fossils from these beds represent a stage 

 somewhat higher in the Cretaceous than those of the Dunvegan 

 rocks, but closely resemble them as well as those of the La- 

 ramie series. Meek writes : — " The group of fossils found in 

 the dark indurated clay Gr is, in several respects, a very interest- 

 ing one, not only because every species is new to science, and all 

 of them entirely different from any yet found in any other loca- 

 lity, or eren in any other beds of this locality (with possibly one 

 or two exceptions), but on account of their modern afiinities. 

 Here we have, from beds certainly overlaid by 1000 feet of 

 strata containing Cretaceous types of fossils, a little group of 

 forms presenting such modern affinities that, if placed before 

 any palaeontologists unacquainted with the facts, they would be 

 at once referred to the Tertiary." 



In the Peace River district we have, instead of a merely- 

 local intercalation of this character, a widely extended series of' 

 Cretaceous beds persistently holding fresh-water and estuarine.; 

 types of molluscs and land plants. 



The chief evidence of the Tertiary age of the Laramie and" 

 Fort Union beds, after that afforded by the plants, has been; 

 found in the Tertiary aspects of the molluscs, most of which 

 are fresh- or brackish-water forms. Hitherto little has been. 

 known of the fresh-water fauna of the undoubted Cretaceous; 

 Dut if this should prove to have, as now appears probable, a 

 " Tertiary " aspect throughout, it will tend to break down the- 

 molluscan evidence of the Tertiary age of the Laramie, and' 

 unite this formation still more closely with the underlying beds.. 



March 1, 1881. 



* U. S. Geol. Survey of Territories, 1872, p. 435. 



