662 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
valve. This group of characters is unlike that of any other species. In the other 
described species the sulcus in the pedicle fold originates farther toward the pos- 
terior and the costa of the sulcus in the brachial valve is stout and angular rather 
than slender as in O. inexpectata. 
OLIGORHYNCHIA SUBPLANA Cooper 
Plate 124, B, figures 14-17; plate 124, EF, figures 26-31; plate 125, B, figures 16-36; 
plate 125, C, figures 37-46; plate 125, D, figures 47-49 
Oligorhynchia subplana Coorer, Amer. Journ. Sci., ser. 5, vol. 20, pp. 49-52, pl. 1, figs. 2, 8, 
13, 14; text figs. I-4, 1935. 
This species differs from O. angulata Cooper in its narrower outline, less angu- 
lar folds, and its ornamentation. 
Types.—Holotype: Y.P.M. S2251; paratypes: Y.P.M. S2253-2257; figured 
hypotypes: 118014, 117200a,b, 117201a,b, 117202a,b. 
Horizon and locality—Lincolnshire formation (Hogskin member) in Tennes- 
see: At Luttrell, Luttrell (T.V.A. 155-NW) Quadrangle; 3 to 44 miles west- 
southwest of Thorn Hill on the road to Washburn, Avondale (T.V.A. 162-SW) 
Quadrangle; 2 miles southwest of Hall Crossroad, Fountain City (T.V.A. 
146-SW) Quadrangle; south side of the school just north of Chesney railroad 
crossing, Luttrell (T.V.A. 155-NW) Quadrangle; Maynardville Pike, 1.7 miles 
north-northeast of Hall Crossroad, Fountain City (T.V.A. 146-SW) Quad- 
rangle; on U. S. Highway 25E, 3 mile north of Indian Creek, Howard Quarter 
(T.V.A. 162-NW) Quadrangle; 4 mile southwest of Fleanor Mill, 200 yards 
north of the highway, Powell Station (T.V.A. 137-SE) Quadrangle; 3 mile 
southwest of Mount Eager Church, Hogskin Valley, Powder Springs (T.V.A. 
154-SW) Quadrangle. 
Ward Cove formation in Tennessee: 3 mile southwest of Mount Eager Church, 
Hogskin Valley, Powder Springs (T.V.A. 154-SW) Quadrangle. 
Sevier formation in Tennessee: + mile northeast of Miser, Louisville (T.V.A. 
138-SE) Quadrangle. 
Lincolnshire formation in Virginia: 33 feet above the base, along the highway 
beside Tumbling Run, 14 miles southwest of Strasburg, Strasburg (15’) 
Quadrangle. 
OLIGORHYNCHIA SUBPLANA GIBBOSA Cooper 
Plate 125, A, figures 1-15; plate 125, E, figure 50 
Oligorhynchia subplana gibbosa Coorer, Amer. Journ. Sci., ser. 5, vol. 20, p. 52, pl. 1, figs. 1, 
3-5, 12, 1935. 
Types.—Holotype: Y.P.M. S2252; figured hypotypes: 90751, 111304. 
Horizon and locality—tLincolnshire formation (Hogskin member) in Ten- 
nessee: 3 to 44 miles west-southwest of Thorn Hill on the road to Washburn, 
Avondale (T.VA. 162-SW) Quadrangle; Luttrell, Luttrell (T.V.A. 155-NW) 
Quadrangle. 
