Descriptions of Species. 33 



Cylindrites (?) sp. indet. 



The writer has collected from the base of the Glen Rose beds 

 in Parker county a few specimens of a small gasteropod very 

 much resembling Cylindrites buliatus Lye. and Mort. Unfortu- 

 nately the specimens have been lost. 



Buccinopsis (?) parryi Conrad. 

 Plate VI, Fig. 1. 



U. 8. and Mexican Boundary Report, p. 158, plate xiii, figs. 

 4a, b. 



/?. Conradi Hill. Arkansas Geological Survey, Annual Report 

 1888, vol. n, p. 130, plate iii, figs. 2, 2a. 



Conrad describes this species as follows : 



" Subpyriform ; longitudinally undulated and ornamented 

 with rugose, revolving lines, spire scalariform ; aperture large 

 and patulous." Conrad also says : " Under this name I have 

 described a cast which cannot be referred to any known genus; 

 it is certainly not a true Buccinopsis, nor can its generic char- 

 acter be determined because of poor preservation." 



I 



The writer has found casts of this form in great .abun dance in 

 the lower fossiliferous horizons of the Glen. Rose bed at gypsum 

 bluffs of the Little Missouri, in Arkansas, and at Glen Rose. In 

 some instances the casts show marks in the shape of depressions 

 extending across the lower whorl and the sutures are very deep 

 and distinct. The whorls and spire of a more perfect specimen, 

 shown in plate vi, fig. 1, arc six in number and very flat 

 and angular at their upper edge. Whatever may be the true 

 generic position of this form, it is a very useful stratigraphic aid 

 to the student of the Glen Rose beds. The form is readily dis- 

 tinguishable from Tyloiftoma pcdernalis Roemer by its greater 

 number of whorls and entirely different outline of the aperture. 



Tylostoma pedernalis (Roemer). 

 Plate VI, Fig. 2. 



Natlca pedernalis and N. prxgmndis Roemer. Kreidebildungen 

 von Texas, p. 43, plate iv, figs, la, b; plate iv, figs, la, b. 



"Shell large, ovate; whorls flat, angular above; lowest or 

 basal whorl three times as high as the spire; spire composed of 

 three coils. Aperture, elongate ovate." Roemer 



5 BIOL. Soc. WASH., VOL. VIII, 1893, 



