964 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
Highway 11, Edinburg (15’) Quadrangle; opposite dam, North Fork of the 
Shenandoah River, 14 miles N. 61° E. of Edinburg, Edinburg (15’) Quad- 
rangle; U. S. Highway 11, 14 miles southwest of Strasburg, Strasburg (15’) 
Quadrangle. 
Discussion—This species has the large and prominent myophore crest of the 
genus, but is large and circular in outline. It is more finely costellate and larger 
than C. cristata, the only other known species of the genus. Tentatively referred 
here are some specimens occurring just under the Eureka quartzite in dark shales 
in Nevada on the north-facing nose of hill 8167, Martins Ridge, Roberts Moun- 
tains (1°) Quadrangle. This occurrence emphasizes the strong faunal relations 
between this shale and the Oranda formation of Virginia. 
Genus HOWELLITES Bancroft, 1945 
HOWELLITES sp. 
Plate 145, E, figures 29, 30 
Howellites BANcRorT, Journ. Paleont., vol. 19, No. 3, p. 203, 1945. 
Figures of the exterior and interior of the brachial valve of Howellites are 
introduced for comparison with Paucicrura, Cristiferina, and Eremotrema. 
Figured specimen.—83859a. 
Horizon and locality—Upper Ordovician (Soudleyan), Allt Fawr, Meifod 
District, Montgomeryshire, Wales. 
Family PAURORTHIDAE Opik, 1933 
Dalmanellacea with a simple cardinal process, brachiophores simple and sup- 
ported by notothyrial platform. 
Genus PAURORTHIS Schuchert and Cooper, 1931 
Paurorthis ScHUCHERT and Cooper, Journ. Paleont., vol. 10, No. 7, p. 243, 1931; Mem. 
Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 79, 1932.—Or1x, Acta et Comment. Univ. Tartu, 
ser. A, vol. 25, No. I, p. II, 1933. 
PAURORTHiIS CATAWBENSIS Butts 
Plate 151, G, figures 30-36; plate 162, D, figures 19-23 
Paurorthis catawbensis Butts, Virginia Geol. Surv. Bull. 52, p. 67, pl. 80. figs. 11-13, 1942. 
Shell of about average size for the genus, slightly wider than long with great- 
est width at about the middle. Cardinal extremities rounded. Lateral margins 
gently rounded, anterior margin narrowly rounded. Anterior commissure broadly 
sulcate. Surface multicostellate ; costellae rounded, with very narrow interspaces. 
Fascicles low ; about 5 costellae in the space of I mm. at the front. 
Pedicle valve moderately convex with the greatest convexity located in the 
umbonal region when seen in lateral profile. Narrowly rounded in anterior pro- 
file. Fold obscure, defined as a longitudinal swelling extending from the beak 
