FOSSIL MOSSES. 

 By Elizabeth G. Br it ton. 



IN A collection of fossil plants made by Prof. I. C. Russell at a coal 

 mine one mile west of Cle Eltim, Kittitas county, Washington, 

 on July yth, 1897, in what is known as the Roslyn sandstone. 

 Prof. Knowlton found a small fossil moss. He states its age as 

 probably lower Miocene or upper Eocene, and says it is associated 

 with a number of beautifully preserved leaves of Elms, Plane trees 

 and Sapodillos, whose nearest living relatives in this country now in 

 existence is the Persimmon, besides a species of Lygo- 

 diiiin not far removed from our Climbing Fern. Prof. 

 Knowlton states that this is possibly the oldest fossil 

 species thus far found in this country, and he sent it to 

 me for the determination of its living alliance. In spite 

 of its being imbedded in a sandstone, the carbonaceous 

 remains of the stem and leaves is still very soft, and 

 shows distinctly, especially when moist, the black stems 

 which seem to have a prolongation at the apex into a 

 leafless stolon. This is not unusual in certain of the 

 creeping species of mosses, which spread by means of 

 these young shoots. The leaves are of a delicate brown 

 color, and seem to be nearly, though not quite, two- 

 ranked. This is very interesting, for it indicates at once 

 that the specimen belongs to one of those genera of the 

 Hypnacese with flattened, nearly distichous leaves, such 

 as Plagiothecium or Rynchostegium, several species of 

 which also taper off at the apex into slender stoloniferous 

 stems, with the leaves diminishing in size as they approach 

 the apex. On a few of the lower leaves, however, there 

 is a trace of what appears to be unmistakably a vein, and 

 this would render it more than probable that this is a 

 species of Rynchostegium, as the Plagiotheciums have 

 two short, inconspicuous veins. Therefore I have de- 

 Fossii Moss. En g^ribed it as a new species of this genus and dedicated it 



larged eight ^ ° . . 



times. to its discoverer, RJiyncostegium Knoivltoni, E. G. Britton 

 {Bull. Torr. Bot. Club, 26: 1S99). The accompanying figure, in which 

 the specimen is eight times enlarged, shows the shapes of the leaves, 

 which are short and broad and have an acute apex. They were drawn 

 with a camera lucida from the actual specimen by Dr. Arthtir Rol- 

 lick, and certain imperfections in preservation have not been corrected. 

 Dr. Hollick also looked up the literature of fossil mosses and found 



