Descriptions of Species. 27 



ing. (See U. S. and Mexican Boundary Report, vol. i, p. 148, 

 plate Hi. figs. 2, 6, c.) Occurs abundantly in the plant beds of 

 the Paluxy. The species is named for Professor G. W. Stolley, 

 of Austin, Texas, whose work as a collector is esteemed in both 

 Europe and America. 



Trigonia crenulata Roemer. 



Plate III, Fig. 4. 

 Rocmer. Kreidebildun .-;en von Texas, p. 51, plate vii, fig. 6. 



This species, described by Roemer from imperfect casts, may 

 be the same as T. stolieyi The specimen here figured was col- 

 lected from the bluffs of the Colorado near Bull creek, Travis 

 county. 



Chione (?) decepta sp. nov. 

 Plate I, Figs. 9 and 10. 



Shell sub-triangulate or elliptical in outline, compressed in 

 cross-section from base to umbones ; umbones forward of center, 

 small, and touching each other; lunular area small, cordate oval ; 

 pallial margin widely rounding; anterior cardinal margin con- 

 cave, shorter than posterior ; posterior cardinal margin long, 

 slightly con vex, asymmetrical; cardinal mechanism not shown; 

 surface marked by long concentric and very faint irregular lines, 

 anterior muscular scar elongate, rounded; posterior muscular 

 impression flat, depressed at extreme posterior end. 



The casts of this form are abundant throughout the Glen Rose 

 beds, but its generic position is uncertain. It may possibly be- 

 long to the Carditidas. In the hills north of Lampasas, near 

 the top of the formation, the specimens occur in great abundance 

 with the shell preserved in calcite, showing the exterior structure. 

 Conrad's species of Astarte texana* described from a cast from 

 an unknown locality, has a superficial resemblance to this form, 

 according to his description and figures, but it is more triangular 

 and otherwise different, as seen by comparison with his type in 

 the National Museum. 



* TJ. S. and Mexican Boundary Report, vol. i, p. 152, plate v, fig. 9. 



