C. A. White — Puget Group of Washington Territory. 447 



that an arboreal flora extended entirely across it, and scattered 

 its autumnal leaves into the Laramie sea upon the one hand 

 and into the Puget estuary on the other. Possibly it may 

 yet appear that terrestrial vertebrate, and molluscan faunas also 

 extended across the same area by the discovery of their re- 

 mains in both the Laramie and Puget groups. 



Besides the evidence which is furnished by the character of 

 the gill-bearing fossil mollusca of the Laramie and ' Puget 

 groups respectively that they were deposited in separate bodies 

 of water, satisfactory evidence exists that the Laramie outlet 

 was upon the Atlantic side of the continent, and that the 

 Puget outlet was upon the Pacific side. Admitting that these 

 conditions existed there seems to be little probability that 

 the two faunas had a common origin. Under such circum- 

 stances I think it better to use separate names for the two for- 

 mations ; and I have accordingly proposed the name of Puget 

 Group for the formation which forms the subject of this article. 



As to what were the original boundaries of the Puget estu- 

 ary deposit comparatively little is definitely known, as already 

 intimated. It is probable also that much will always remain 

 unknown upon this point owing to the great erosion which the 

 strata have suffered, and to the presence of large portions of 

 the volcanic outflows which have so largely covered them. 

 Taking into consideration the extreme points at which strata of 

 this group have been found, including those which lie to the 

 east of, and among the Cascade mountains, the present indica- 

 tions are that the Puget Group originally occupied an area of 

 several thousand square miles. 



That the body of water in which the Puget Group was de- 

 posited was an estuary, and not a land-locked sea, as was the 

 Laramie, is indicated, as already shown, by its molluscan fauna.* 

 But in what manner the Puget estuary was separated from the 

 open ocean we have as yet little information. A natural infer- 

 ence would be that the Olympic island formed part of such a 

 barrier, but the discovery of marine fossils in the valley of 

 Dwamish river, the strata inclosing which were presumably 

 formed contemporaneously with at least a portion of the Puget 

 Group, would seem to show that the estuary barrier was, a part 

 of the time, at least, to the eastward of Olympic island. 



Although the contemporaneity of the Puget and Laramie 

 groups apparently need not be questioned, the stratigraphical 

 relation of the former to the Tejon Group, which is presuma- 

 bly of approximately the same age, has not been satisfactorily 

 determined. Vertebrate and vegetable paleontology have fur- 



* The apparent absence of this peculiar fauna from the more eastern strata sug- 

 gests that they were deposited nearer to the* influx of fluviaiile waters, which 

 being therefore entirely fresh did not afford a congenial habitat for the species 

 which prevailed in the western and brackish part of the estuary 



