1895.] NATURAL SCIENCES OF PHILADELPHIA. 159 



deposits would be somewhat unconformable to the lower and 

 submerged ones and would have an appreciable quantity of shore 

 debris mixed with the cleaner marine sands. 



This is the condition in which we find the lower deposits of the 

 Fayette sands. These beds are irregular in form, wedge-shaped ( 

 cross-bedded and often lenticular, the whole indicating a deposition 

 in very shallow water subject to a strong sweep of the tide and often 

 affected by storms. The life of the time as represented in these beds 

 shows leaves, stems and trunks of trees belonging to low- lying, 

 marshy lands. Palm wood is plentiful while the stems and leaves 

 of the palmetto, , rushes and marsh grass may be found in some 

 localities in abundance, showing that when these beds were being 

 deposited the marshy tracts of the Yegua clays to the northward 

 were still the home of such growths. None of these are indigenous 

 to the Fayette sands and exist there only in the form of drift material 

 cast up by the sea. Near the top of the Fayette sands we find 

 trunks and limbs of trees of large size, many of them even now 

 showing diametrie measurements of over three feet, and although some 

 show a length of 25 or 30 feet the greater portion of the logs do not 

 exceed ten or twelve feet in length. Occasionally a stump with the 

 larger roots attached may be found, but this exceedingly rare. A 

 peculiarity regarding these trees is that they are every one in the 

 form of wood opal or in an opalized condition, vitreous and clear 

 when broken, breaking with sharp cutting edges and retaining every 

 mark and line of growth as it appeared in the tree. The outside of 

 these woods is generally a dull white showing a process of decay. 

 This form of wood is peculiar to the Fayette sands and occurs 

 nowhere else within the Texan regions. 



The faunal life connects these beds with the whole series of the 

 Eocene stages as shown in the Texan section and is decidedly marine 

 in every phase. Venericardia planicosta Lam., CalyptrophoruS 

 velatus Con., Mactra sp., Dentalium minutistriatum Gabb, var. 

 dumblei Harris and Corbula alabamensis Lea, as well as many others 

 represent the inhabitants of this portion of the sea at that time. 



To the southward the land was sinking and the sea creeping 

 farther up over the Fayette shores. A deposit of clay was being 

 laid down which within a short time was destined to become the last 

 representative of Eocene times in this portion of the world. These 



