PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 861 
Measurements in mm.— 
Brachial Hinge ) 
Length length Midwidth width Thickness Height 
FHOLOLY PEs sites So sishe soe 15.0 II.9 90.3 9.4 4.3 7.4 
Paratype (97536a)....... 9.0 ? 9.7 10.7 ? 2.2 
3 (07536D)) =)... ive 10.5 ? 9.1 9.5 ? 4.3 
a CUETOOSD)).saic1-:< 13.5 10.0 9.7 0.4. 4.5 eat 
a (ir) ee 16.9 13.1 Dies 10.6 ? 5.6 8.0 
2 ENS 7 E Te cts 14.8 eres 10.9 10.1 3.8 7.3 
EB 75724) Se 18.1 13.9 11.4 117 fy 9.6 
Types——Holotype: 97537a; figured paratypes: 97537b, I11005b, 117570, 
117571; figured cotype of C.t. brevis Butts: 97536b; unfigured cotype C.t. brevis 
Butts: 97536a; unfigured paratypes: 97537c, I11005a, 117572a-c. 
Horizon and locality—Oranda formation in Virginia: Along the railroad 
4 mile west of Strasburg, Strasburg (15’) Quadrangle; 200 yards on Virginia 
County Highway 616, southeast of U. S. Highway 11, 3.5 miles southwest of 
Mount Jackson, Mount Jackson (15’) Quadrangle ; junction of Virginia County 
Highways 691 and 692, west of Lantz Mills, Edinburg (15’) Quadrangle; on 
Virginia Highway 55, 0.4 mile west of U. S. Highway 11, on the north edge 
of Strasburg, Strasburg (15’) Quadrangle; just east of the junction of Vir- 
ginia County Highways 617=910, and 777, 4 mile north of Green Mount Church, 
Broadway (15’) Quadrangle; on U. S. Highway 11, 4 mile southwest of 
Tumbling Run, southwest of Strasburg, Strasburg (15’) Quadrangle; at the 
dam on Shenandoah River, 14 miles N. 61° E. of Edinburg, Edinburg (15) 
Quadrangle ; Bowman Farm, east side of U. S. Highway 11, 1 mile southwest 
of Woodstock, Edinburg (15’) Quadrangle. 
Discussion.—This species is characterized by its elongate form, somewhat con- 
cave sides, presence of distinct ears on the cardinal extremities, and its consider- 
able depth. It differs from C. platys in its greater depth and different shape. 
From C. subquadrata it differs in generally attaining a greater size, in being 
somewhat more elongate, and in having definite and fairly prominent ears on the 
cardinal extremities. 
A brachial interior of this species compared to the single interior known of 
C. trentonensis shows general similarity, but the Oranda specimen is more con- 
vex. As presently understood the European species C. tenwicincta (McCoy) 
includes too wide a range of variation for accurate comparison with the Ameri- 
can species. Christiania oblonga (Pander) is a much smaller and more slender 
species. 
CHRISTIANIA PLATYS Cooper, new species 
Plate 210, D, figure 11; plate 214, B, figures 3-5; plate 215, B, figures 5-10; 
plate 215, G, figure 29 
Shell large and broad for the genus, subquadrate in outline and with the 
length and width nearly equal; sides nearly parallel; anterior margin broadly 
rounded ; hinge nearly equal to the width, slightly auriculate. Surface marked 
by concentric growth lines only. 
