PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 95! 
sulcate. Costellae strong, narrowly rounded or subangular, numbering about 2 
to the millimeter at the anterior margin. Interspaces with strong fila often pro- 
ducing a beaded effect. 
Pedicle valve moderately strongly convex in lateral profile with the maximum 
convexity just posterior to the middle; anterior profile strongly convex and with 
steep lateral slopes. Umbo narrowly rounded, the folding continuing to a point 
at or just anterior to the middle. Median region swollen; anterior and lateral 
slopes convex, steep. Beak incurved; interarea short, curved, apsacline. 
Brachial valve evenly and moderately convex in lateral profile; broadly and 
gently convex in anterior profile but with the median region gently depressed ; 
umbo sulcate, the sulcus increasing in width anteriorly where it is broad and shal- 
low ; flanks bounding sulcus gently inflated. Interior of young brachial valves with 
convergent and subparallel brachiophore plates but poorly developed fulcral 
plates. Cardinal process small, with thin shaft. Adults with thickened and en- 
crusted brachiophores and fulcral plates obsolete. Anterior adductor pair much 
larger than the posterior pair. 
Measurements in mm.— 
Brachial Hinge 
Length length Width width Thickness 
BIGGER E) os )oss He biais aus 11.0 10.3 11.5 6.4 5.8 
Paratype (117364a)... 10.0 9.0 10.0 6.2 4.5 
* (117364b) . 3. 7-5 6.8 7.4 4.6 3.7 
Types—Holotype: 117364c; figured paratypes: 117364a,d,e; unfigured para- 
types: 117364b,f-1. 
Horizon and locality—Martinsburg formation (part with Brongniartella= 
Salona formation) in Broadway (15’) Quadrangle, Virginia: On Virginia 
County Highway 617=910, about 0.15 mile north of Green Mount Church; 
0.6 mile northwest of Linville Station. 
Discussion.—This species is characterized by its circular outline, small, sub- 
erect beak, gentle sulcus, moderately strong costellae with prominent fila that 
often produce a beaded effect on the costellae. The species is suggestive of 
D. costellata which occurs in the Oranda formation just below the Salona. It 
differs, however, in not having the oval form and fine ribbing of the Oranda 
species. 
This species shows an interesting feature besides the development of the 
beaded costellae. In two specimens the myophore has a high-crested median 
ridge suggestive of Cristiferina, but the cardinalia are not like those of that 
genus. The beak regions of many specimens were cleaned out in an effort to 
learn the constancy of this feature, but most of the specimens, after careful 
preparation, failed to show the strong myophore crest. 
DALMANELLA SULCATA Cooper, new species 
Piate 161, A, figures 1-16 
Shell of about medium size for the genus, subrectangular in outline; wider 
than long; maximum width at or near the middle; hinge narrow, about two- 
