PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 947 
ada: On Lot 24, concession VII, Allumette. In Ontario: At Mechanicsville, 
Ottawa. 
STROPHOMENA sp. 1 
Plate 257, C, figures 13-15 
This species is known only from adult brachial valves and fragments of the 
pedicle valve. The brachial valve is strongly convex in lateral profile and has 
the maximum convexity located at about the middle. The anterior profile is 
broadly and strongly convex. The umbonal region is gently convex and forms 
a steep slope—steeper than the anterior one. The median region is strongly 
inflated. This Nevada species is most like S. planobesa, new species, in its pro- 
files and general form, but it is more convex and has a somewhat different outline. 
Figured specimen.—117742Aa. 
Horizon and locality.—Just beneath the Eureka sandstone in Nevada: In the 
Antelope Range on the west side about 3 miles south of Ninemile Canyon, 
Roberts Mountains, (1°) Quadrangle. 
Suborder DICTYONELLOIDEA Cooper, new suborder 
Shells having a smooth umbonal attachment for the pedicle. 
Family EICHWALDIIDAE Schuchert, 1893 
Usually triangular shells with narrow lateral grooves in the brachial valve for 
articulation. 
Genus EICHWALDIA Billings, 1858 
Eichwaldia Bitirncs, Geol. Surv. Canada, Rep. on Progress for 1857, p. 190, 1858. 
EICHWALDIA SUBTRIGONALIS Billings 
Plate 163, A, figures 1-6 
Eichwaldia subtrigonalis Bittrncs, Geol. Surv. Canada, Rep. on Progress for 1857, p. 192, 
fig. 24, 1858; Canadian Nat. Geol., vol. 3, p. 443, fig. 24, 1858; Geol. Canada, p. 142, 
fig. 76, 1863.—Hatt and CLarxe, Pal. New York, vol. 8, pt. 2, p. 310, figs. 241, 242, 
pl. 83, figs. 1-4, 1893—Wzutson, Geol. Surv. Canada, Bull. 8, p. 120, pl. 8, figs. 6-9, 1946. 
Types——Holotype: G.S.C. 1145a; paratypes: G.S.C. 1145b-g; hypotype: 
G.S.C. 6418; figured hypotypes: U.S.N.M. 92360d,f. 
Horizon and locality—Rockland formation in Canada: Paquette Rapids, 
Ottawa River, Ontario; Allumette Island, Ottawa River, Quebec. 
Suborder DALMANELLOIDEA Moore, 1952 
Punctate brachiopods with orthoid-type cardinalia. 
Superfamily DALMANELLACEA Schuchert and Cooper, 1931 
Family DALMANELLIDAE Schuchert, 1929 
(= WarTTSELLIDAE Schuchert and Cooper, 1931) 
Dalmanellacea with subcircular or shield-shaped shells having a cordate pedicle 
muscle field and fulcral plates defining the sockets. 
