26 Hill Paleontology of the Trinity Division. 



This is one of the most characteristic species of the very base 

 of the Glen Rose beds in Parker, Hood, and Comanche counties, 

 and is the form which the writer once inferred to be analagous 

 to Ambonicardia cookii Whitfield,* from the Raritan clays of 

 New Jersey, which the fragments then found strongly resem- 

 bled in outline and marking. The discovery of the specimen 

 here figured, however, for the first time affords evidence for their 

 satisfactory generic identification. 



The specimen figured was found about three miles east of 

 Millsap. Texas, at the contact of the Trinity sands and the cal- 

 careous Glen Rose" beds. I have also found the species near 

 Springtown, Parker county, and at Comanche, in the same hori- 

 zon. 



Cucullsea terminalis Conrad. . 



(See Report United States and Mexican Boundary Survey' 

 Washington, 1857, vol. i, p. 148, plate iv, figs. 2a and ft.) 



Casts of this species are frequently met with in the Glen Rose 

 beds. The shell has not yet been found. 



Barbatia parva-missouriensis Hill. 



This species, from Pike county, Arkansas, was described and 

 figured in my Arkansas Report, p. 133, plate iv, figs. 4a, 4ft, 5, 

 and probably fig. 22, of plate ii, of same report. 



Trigonia stolleyi sp. nov. 

 Plate III, Figs. 3 and 5. 



Semi-lunate in general outline, beaks well forward and strongly 

 recurved ; anterior and pallial margin a strong continuous curve 4 ; 

 posterior portion elongated with truncated posterior margin ; 

 cardinal area compressed. Surface marked by flexuous, noduled 

 costsc, about twenty -two in number, narrow and high, separated 

 by broad intercostal areas as in T. alfefoi v niis Link. ; depressed 

 cardinal area bordered on its outer side by a long narrow groove 

 and marked by cross-ribs, flexing anteriorly. 



This Trigonia differs from T. emoryi Conrad, of the Washita 

 Division, in its general outline and entirely distinct surface mark- 



*See Report of Arkansas State Geological Survey for 1SSS, vol. n, p. 

 126. 



