Descriptions of Species. 21 



This important ibramiriifer was first found by Roemer on the 

 upper branch of the Pedernalis, associated with Tylostoma peder- 

 nalis. I have found its true position to be in the medial por- 

 tion of the Glen Rose beds, where, as on the Colorado near the 

 mouth of Bull creek, it occurs in a massive chalk some ten feet 

 thick. The "Orbitolina " beds are among the most characteristic 

 and distinguishing features of the upper Neocomian of Europe, 

 in the region of Jura, and in Dauphine, Portugal, and Spain. 

 Their occurrence in a similar stratigraphic position in the Texas 

 region is additional evidence of "the Neocomian age of the Glen 

 Rose beds. This Texas form has also been reported by Karsten 

 from the Neocomian beds of Venezuela. 



ECHINODERMATA. 

 Epiaster (?) sp. indet. 



Only one echiiioid has come under the writer's observation 

 from the Glen Rose beds. It occurs about midway in the sec- 

 tion, near Bull creek, Travis county, and in Somervell county, 

 Texas. This has been submitted to Professor W. B. Clark, of 

 Johns Hopkins University, who writes as follows concerning it: 

 " I am inclined to think it not only a new species, but a new 

 genus." The specimens are left in Professor Clark's hands for 

 future determination. 



VERMES. 



Serpula paluxiensis sp. nov. 

 Plate I, Figs. 4, 4a, 46. 



Cylindrical tubicolate, marked by concentric lines of growth; 

 occurs in colonies, radiating out from a central nucleus. Indi- 

 viduals several inches long, but it is impossible to trace com- 

 plete length of specimens, owing to mode of growth. Adult 

 specimens average one-eighth inch in diameter. 



This is one of the most abundant forms in the basement hori- 

 zon of the Glen Rose beds, and occurs attached to lignite, shells 

 of OstreiddSj and casts of other mollusks, or" in immense colonies 

 or spherical masses, some of which in Paluxy creek, averaging 

 three feet in diameter, are composed entirely of this species. 



