PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 843 
Salona) in Virginia: On County Highway 617=910, 0.15 miles north of Green 
Mount Church, Broadway (15’) Quadrangle. 
Discussion—This is the largest known species of the genus and in its adult 
form is thus readily distinguished from the other two known species. It is pro- 
portionately wider than the other two and is somewhat more strongly costellate. 
CYPHOMENA HOMOSTRIATA (Butts) 
Plate 223, D, figure 7; plate 224, B, figures 9-20 
Leptaena homosiriata Butts, Virginia Geol. Surv. Bull. 52, p. 110, pl. 95, figs. 24, 25, 1942. 
Small, subrectangular in outline and with the hinge forming the widest part; 
sides gently oblique; anterolateral extremities narrowly rounded; anterior mar- 
gin gently convex to truncated. Surface finely costellate, 4 to 6 costellae in a 
millimeter at the front margin of an adult. 
Pedicle valve strongly convex in lateral profile, the greatest convexity located 
at about the middle; anterior profile domed and with steep sides but the median 
part depressed by a sulcus. Visceral region nearly flat in profile; geniculated 
part narrowly rounded; trail gently convex in lateral profile. Visceral region 
gently convex; trail moderately long and marked by a prominent sulcus. Flanks 
of trail bounding sulcus rounded and somewhat swollen. 
Brachial valve gently concave, the deepest part located near the place of genicu- 
lation. Visceral region gently concave. Trail short, marked medianly by a low 
and inconspicuous fold. Muscle area narrowly arrow shaped, moderately 
thickened. 
Measurements in mm.— 
Brachial Hinge Thick- Surface Trail 
Length length Midwidth width ness length length 
ELGOLY HE coca cet ets 8.1 7.4 10.4 Ties 3.2 13.5 6.0 
Paratype (117622).... 7.7 6.6 10.3 ? 3.0 II.5 6.0 
§ (117623a)... 8.2 7.4 11.7 rise PY | 11.5 6.0 
Types—Holotypes: 97545, figured hypotypes: 117615, 117622, 117623, 
117624. 
Horizon and locality—Oranda formation in Virginia: Along the railroad 
4 mile west of Strasburg, Strasburg (15’) Quadrangle; on the Shenandoah 
River, 14 miles N. 61° E. of Edinburg, Edinburg (15’) Quadrangle; Bowman 
Farm, 0.3 mile east of U. S. Highway 11, on the south edge of Woodstock, 
Edinburg (15’) Quadrangle ; just west of the junction of Virginia County High- 
ways 617=910, and 777, about 4 mile north of Green Mount Church, Broadway 
(15’) Quadrangle. 
Oranda formation in Pennsylvania: 13 miles west of Kauffman, 4 mile north 
of Greencastle, Chambersburg (15’) Quadrangle. 
Discussion.—This species is the smallest of the three known species and is 
generally somewhat squarer than the other two in outline. It is also somewhat 
more finely costellated and has a somewhat flattened umbonal region. It is usu- 
ally not so alate as C. angulata. 
