1895.] NATURAL SCIENCES OF PHILADELPHIA. 45 



NEW AND OTHERWISE INTERESTING TERTIARY MOLLUSCA 



FROM TEXAS. 



BY GILBERT D. HARRIS. 



While employed as Tertiary paleontologist to the Geological Survey 

 of Texas during the years 1892 and 1893, the writer prepared a large 

 monograph on the Tertiary mollusca of the State with the intention 

 of publishing it in the 5th Annual Report of that Survey. For 

 want of funds the printing of this report has been indefinitely post- 

 poned, and accordingly the following facts and descriptions of new 

 species, taken from the monograph in question, have here found an 

 appropriate place for publication. 



The points in stratigraphy brought out by the study of the various 

 Tertiary faunas of the State have been included with other matter 

 in an article published by the State Geologist in the Journal of 

 Geology, 1894, p. 549. 



Suffice it to say here that the Midway stage, so well developed in 

 Georgia and Alabama and known also in Mississippi and Arkansas, 

 exists also in Texas, as is proved by the occurrence of such species as 

 Enclimatoceras ulrichi, Ostrea pulaskensis, Cucullcea macrodonta, 

 Volutilithes limopsis and others. 



The Lignitic stage, so far as has been observed, is destitute of 

 molluscan remains. The exposure on Brazos River, known as 

 "Smiley's Bluff," two miles above the mouth of Pond Creek, is 

 evidently about synchronous with the Matthews Landing beds of 

 Alabama. These are now included in the Midway stage. 



The Lower Claiborne beds are replete with fossils, many of which 

 are common to this horizon in Louisiana, Mississippi, Alabama, and 

 South Carolina. Besides these well-known forms there are many 

 new ones, some of which are described below. 



The true Claiborne, the Jackson, and the Vicksburg stages seem 

 to have no representatives in Texas. This fact cannot be too 

 strongly emphasized since most writers on Texas geology have re- 

 ferred certain fossil bearing outcrops to some of these upper Eocene 

 stages. 



