152 PROCEEDINGS OF THE ACADEMY OF [1895. 



fossil been found and even the lignite so plentiful in the upper clayey 

 portion of the lignitic appears to be wanting altogether or is ex- 

 tremely scarce. From this condition we might infer that the coast 

 line was for a long time faced by a broad expanse of littoral sands, 

 over which the sea flowed intermittently and at irregular periods, 

 and at different depths, carrying with its waves enormous, although 

 irregular quantities of sand. The fresh water streams, with the ex- 

 ception of the two rivers, the Brazos and Trinity, having no fixed 

 channels spread their deposits over the sands to be afterwards re-ar- 

 ranged by the succeeding tidal waters. 



The marine action being intermittent the sandy shores would 

 necessarily be exposed to atmospheric agencies for frequent and 

 probably considerable periods of time, while the fresh water deposits 

 would be thin and widely spread, and disturbed if not altogether 

 destroyed, by every inundation of the sea. Under these conditions 

 the irregular thickness of the beds and their indurated portions may 

 readily be accounted for while at the same time they would be ex- 

 tremely inhospitable for molluscan life and any stray shell that might 

 find its way into the region would surfer desiccation and be almost 

 immediately broken to a fine powder. Many of the bays along the 

 southern coast of Scotland present the same features at the present 

 day. There we have a series of deposits of sands and clays forming 

 the immediate shore line elevated from 7 to 10 feet above a broad 

 foreshore of sand, over which the sea only tlows at periods of ex- 

 treme high water or during storms. Immediately in front of othis, 

 to the seaward, lies a belt of sand covered but lightly during 

 "spring " tides and dry during the periods of "neap" or low tides, 

 while again in front of this, we find the life zone or region of niol- 

 lusks. This is covered by every tide that flows. The higher grounds 

 are under cultivation and the fore shore is covered with a scanty 

 vegetation of samphire and other salt-loving plants. This strip 

 forms the well-known "links" of that coast. The two outer 

 zones are totally devoid of vegetation. The same condition of 

 affairs also prevails at the head. of the Bay of Fundy, in Nova 

 Scotia and throughout many other portions of this continent. 



The fauna of this period must be looked for much farther to the 

 south and southwest where marine conditions prevailed altogether, 

 and when the sea was gradually raising up a barrier of sand be- 

 tween itself and the shore. This barrier, by closing out the sea, or 



