PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 243 
rounded. Maximum width at the middle. Sides moderately curved. Valves 
marked by even, concentric lines. 
Pedicle valve evenly and broadly convex in lateral profile with the maximum 
convexity located at the middle ; anterior profile narrowly convex. Valve swollen 
medianly, with steep lateral slopes but a more gentle anterior slope. Apical angle 
go® to 100°. Posterior slope long and gentle. Umbo small, short, narrowly 
swollen. 
Brachial valve somewhat more rounded than the pedicle valve and less con- 
vex in anterior and lateral profiles. Inner border of both valves fairly wide, but 
widest at the posterior. 
Measurements in mm.— 
Length Width 
CURIE BS retest at Sci, bh, ate dou 9 as acasnsetcueap eoatiaud eu Mauer Ieee 57 3.7 
Paratype) Gi003576) wc enced. 228 ALU. ABBE! 4.0 2.5 
Types.—Lectotype: 661714; figured paratypes: 66171c (b,e, Bassler, 1919) ; 
unfigured paratype : 661714 ; figured hypotypes: 109357b-e,f, 109370a, 109371a,b, 
109378a, 109379a, 109380. 
Horizon and locality—Martinsburg formation (base of Sinuites bed) in Penn- 
sylvania: 2 miles northwest of Kauffman, Chambersburg (15’) Quadrangle; 
along the railroad south of highway crossing, 24 miles southwest of Marion, 
Chambersburg (15’) Quadrangle. 
Oranda formation in Pennsylvania: 1 mile south of St. Thomas, Mercersburg 
(15’) Quadrangle ; 2 miles southeast of Mercersburg, Mercersburg (15’) Quad- 
rangle; just north of Chambersburg and 5 miles south-southwest of Chambers- 
burg, Chambersburg (15’) Quadrangle. 
Botetourt formation in Virginia: 4 miles southwest of Bland: Hoge Farm, 6 
miles southwest of Bland; near Lusters Gate, 3 miles (airline) east of Blacks- 
burg, Blacksburg (15’) Quadrangle; 2 miles northeast of Blacksburg, Blacks- 
burg (15’) Quadrangle; 1 to 2 miles west of Lexington, Lexington (15’) Quad- 
rangle; 14 miles southeast of Harrisonburg, Harrisonburg (15’) Quadrangle; 
on the boundary of the George Washington Forest, 1.8 miles south-southwest 
of Bethel Church, 6 miles (map measure) due east of Harrisonburg, Harrison- 
burg (15’) Quadrangle. 
Botetourt formation in Tennessee: 2 miles south of Albany, Mosheim (T.V.A. 
181-NW) Quadrangle. 
Edinburg formation (Liberty Hall facies) in Virginia: 2 miles southwest of 
Broadway, Broadway (15’) Quadrangle; just northwest of Lee Highway at 
Lacey Springs, Broadway (15’) Quadrangle; 300 feet north of U. S. Highway 
60, 1 mile north of the railroad station at Lexington, Lexington (15’) Quad- 
rangle; 14 miles northeast of Harrisonburg on Lee Highway (U. S. 11), Har- 
risonburg (15’) Quadrangle; 14 miles east of Tenth Legion, Mount Jackson 
(15’) Quadrangle; 1 mile due west of Hollins, Roanoke (15’) Quadrangle; 14 
miles south of Wadesville, Winchester (15’) Quadrangle. 
