OKLAHOMA ACADEMY OF SCIENCE 39 



very striking. A comparison of the newly formed deposits with 

 the oldest travertine of the Arbuckle mountains indicates that the 

 same plant autncics vvere concerned in the construction of all the 

 tra\'ertine furmations. 



A study of travertine as it is now developing in the Arbuckle 

 region reveals n-iany points of interest in regards to the origin of 

 certain types of fossils and more particularly the fossil remains of 

 plants. Fossils are natural'y regarded by the geologists as records 

 v/hicli enal.)le him to determine the relative age of fossil-beanng 

 rocks. Eut the botanist whose observations and researches do not 

 extend beyond the limits of existing plants sees in the vast ma- 

 jority of fossil forms merely imperfect specimens which are im- 

 possible to determine with any degree of scientific accuracj'. The 

 remains of mosses in a fossil condition are exceddingly scanty. 

 Nearly all of the moss forms discovered belong to the Tertiary and 

 Quaternary periods and are closely allied or identical with living 

 species. The mosses no doubt existed during the early geologic 

 periods but the great delicacy of the tissues of most of them may 

 account for their absence from the _ earlier geological formations. 



Plants fossils frequently occur in the form of incrustations and 

 in fact, incrustations which may assume a variety of forms are 

 quite common. The action of calcareous water is well illustrated 

 1.)y the incrustation of plants and more particularly the water 

 miosses that grov/ on the ledges of certain falls on Honey Creek 

 and Falls Creek. The water moss Didymodon, which is restricted 

 to calcareous habitats, grovv's in the form of, dense tufts extend- 

 ing a fraction of an inch to four inches above the surface of the 

 water. These moss tufts absorb water like a sponge and the cil- 

 careous water evaporates from the leaves and stems, carbon diox- 

 ide escapes and calcium carbonate deposits on the outer surfaces 

 of the plants as a white crystalline covering. Naturally the older 

 and submerged portions of the plants gradually decay. The in- 

 crustation increases and the resulting soft and brittle iiormation 

 has vcrj' much the appearance of an aggregate of delicate corals. 

 As this travert'ne becomes older, it hardens into a compact lime- 

 stone. In photographs submitted with the original manuscript Ivjt 

 not herein reproduced, two representative types of travertine are 

 shown ; type specimens of the oldest deposits of travertine. These 

 rocks show two kinds of incrustations that were formed about 

 water mosses as nuclei. 



Travertine of the first type, develops about tufts of Didymodon 

 growing erect on the surface of water falls. The gradual transitions 



