PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 957 
I am grateful to Dr. C. J. Stubblefield, Geological Survey of Great Britain, 
London, for calling my attention to this unhappy situation. 
PAUCICRURA MATUTINA Cooper, new species 
Plate 150, B, figures 6-11 
Shell of about medium size for the genus, subcircular in outline; hinge mod- 
erately wide; sides gently rounded, anterior margin more strongly rounded; 
anterior commissure faintly sulcate; costellae moderately strong, 2 or 3 to the 
millimeter at the anterior margin. 
Pedicle valve gently convex in lateral view ; triangular in anterior profile and 
with flat, long, moderately steep lateral slopes; umbo narrowly convex, the con- 
vexity continued anteriorly to beyond the middle where it becomes less strong ; 
anterior slope gently convex, long, and gently inclined; beak small; interarea 
moderately long, gently curved, apsacline. Interior with strong teeth, short and 
stout dental plates. 
Brachial valve very gently convex in both profiles but with the anterior pro- 
file depressed medially by a shallow sulcus. Umbo sulcate, sulcus widening an- 
teriorly and becoming shallower in the same direction; flanks bounding sulcus 
gently inflated. Interior with stout, short, slightly divergent brachiophores, 
median ridge low, cardinal process with long shaft but small myophore. 
Measurements in mm.—Holotype, length 7.3, brachial length 6.7, width 7.9, 
hinge width 6.2, thickness 3.2. 
Types.—Holotype: 111795a; figured paratypes: 117366a,b. 
Horizon and locality Edinburg formation (lower Cyrtonotella zone) in Vir- 
ginia: In the ravine at the switch just east of Strasburg Junction, Strasburg 
(15’) Quadrangle. 
Shippensburg formation (Pinesburg member-lower part Echinosphaerites 
zone) in Pennsylvania: Along the railroad 2 miles southwest of Marion, Cham- 
bersburg (15’) Quadrangle. 
Same formation in Maryland: On U. S. Highway 40, on the west bank of 
Conococheague Creek, 7 miles west of Hagerstown, Williamsport (15’) Quad- 
rangle. 
Discussion.—This species is one of the earliest dalmanellids so far found in 
the United States. It is characterized by subcircular outline, moderately wide 
hinge, fine costellae, and moderately deep sulcus. It is close to P. virginica but 
has stronger costellae, a less deep sulcus and a more gentle fold on the pedicle 
valve. 
PAUCICRURA ROGATA (Sardeson) 
Plate 157, F, figures 18-24 
Orthis rogata SaRvEsoN, Minnesota Acad. Nat. Sci., Bull. 3, p. 331, pl. 5, figs. 1-4, 1892; 
Amer. Geol., vol. 19, p. 95, pl. 4, figs. 1-10, 1897. 
Orthis (Dalmanella) testudinaria (Winchell and Schuchert, not Dalman), WincHELL and 
ScHucHERT, Geol. Minnesota, vol. 3, p. 441, pl. 33, figs. 17-22, 1895.—HALL and CLarkgE, 
Pal. New York, vol. 8, pt. 1, pl. 5B, figs. 27-31, 1892. 
