Fauna of the Morrow Group 
143 
1900. Orhiculoidea miss our iensis. Beede, Univ. Geo. Surv. Kans., vol. 6, 
p. 56, pi. 8, figs. l“lc. 
Upper and Lower Coal Measures: Fort Scott; Rosedale, Wyandotte 
County; Lansing, Leavenworth County; and Topeka, Kansas. 
1910. Lingulidiscina missouriensis, Girty, Bull. U. S. Geol. Surv., No. 
436, p. 22, pi. 1, figs. 6-10. 
Phosphate beds, Park City formation: Woodruff Creek, Utah; 
Crawford Mountains, Sublette Range, and Thomas Fork, Wyo- 
ming; Montpelier, Idaho. 
1911. Orhiculoidea missouriensis. Mark, Bull. Sci. Lab. Den. Univ., vol. 
16, p. 308, pi. 8, fig. 3. 
Mercer limestone: Cannel Coal Mine, Flint Ridge, Ohio. 
A single specimen of an Orhiculoidea, somewhat crushed, is 
referred provisionally to Shumard’s species. The diameter of 
the shell, a brachial valve, is not greater than 8 mm. and the 
apex is, if any different, slightly more centrally located than 
in the typical representatives of the species, and the posterior 
and anterior slopes more nearly equal. It would not be prac- 
ticable, however, to distinguish specifically the material at hand. 
Horizon and locality. Brentwood limestone: Sawney Hollow, 
Oklahoma (Station 210). 
RHIPIDOMELLID^ 
Genus RHIPIDOMELLA Oehlert 
Rhipidomella altirostris n. sp. 
Plate VIII, figure 5-5c. 
Description, Shell below medium size, sub-pentagonal in 
outline, length and breadth sub-equal, the hinge-line about half 
as long as the greatest width, the latter occurring half way 
between the anterior margin and mid-length of the shell. The 
dimensions of the holotype, a pedicle valve, are: length, 16 
mm. ; width, 17 mm. ; length of hinge-line, 8.3 mm. ; height of 
cardinal area, 4 mm. ; convexity of pedicle valve, about 6 mm. 
Pedicle valve convex, the greatest convexity posterior to the 
middle, the surface sloping from the umbonal region very 
abruptly toward the cardinal extremities, toward the anterior 
and anterio-lateral margins the surface curving very gently at 
first, but very strongly near the margins; beak broad, projecting 
very slightly beyond the cardinal area, incurved; cardinal area 
about half as high as wide, triangular, horizontally striated, 
sharply defined from the umbonal slopes, cardinal angles obtuse. 
