956 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
cate. Hinge narrow; cardinal extremities rounded. Costellae numbering 2, 
rarely 3, to the millimeter at the front margin. 
Pedicle valve shallow, gently convex in lateral profile, broadly triangular in 
anterior profile, the median region subcarinate, the sides flat, long, and mod- 
erately steep. Umbo and median region narrowly convex and forming a nar- 
row, low fold to the anterior margin. Beak low, small; interarea short and 
strongly curved. Interior with small teeth and short, flaring dental plates ; muscle 
area heart shaped, wide. 
Brachial valve nearly flat in lateral profile; very gently convex in anterior 
profile but with the median region gently depressed by a sulcus. Umbo sulcate, 
the sulcus widening to the anterior margin where it is broad and shallow. Flanks 
bounding sulcus gently swollen; lateral slopes gentle. Brachial interior with 
small brachiophores having short supporting plates which are united to the 
median ridge; cardinal process small with slender shaft and small myophore. 
Measurements in mm.— 
Brachial Hinge 
Length length Width width Thickness 
EEOOLY Pe sine aie aes ete we ere 10.2 9.8 11.5 6.5 3.9 
Paratype (11737048) Uii.F 02: Li 11.4 13.0 Fi) 4.2 
Types.—Holotype: 117370b; figured paratypes: 117365c-e, 117370a; un- 
figured paratypes: 117365a,b. 
Horizon and locality—Base of Hermitage formation in Tennessee: Along 
Tennessee Highway 53, from 0.7 to 1.5 miles south of Woodbury, Woodbury 
(15’) Quadrangle. 
Discussion.—This species has usually been referred to Onniella fertilis (UI- 
rich) but the Curdsville form is a larger shell, more transversely elliptical in 
outline, more convex, and with a proportionally wider hinge. The Hermitage 
species is distinctly subcircular in outline. 
Genus PAUCICRURA Cooper, new name 
(Latin paucus, few; crus, leg) 
Dalmanella ScHucHERT and Cooper (not Hall and Clarke), Mem. Peabody Mus. Nat. Hist., 
vol. 4, pt. I, p. 120, 1932. 
In amplifying Bancroft’s genus Resserella, Schuchert and Cooper (1932 
p. 126) restricted Bancroft’s designation of Orthis canalis Sowerby, 1839, in 
Murchison, Silurian System, to the specimen illustrated on plate 13, figure 12a, 
as type of the genus. This selection now proves most unfortunate because the 
specimen chosen is a member of the genus Parmorthis. The two genera, Res- 
serella and Parmorthis, are thus synonyms, and the latter must be suppressed 
in favor of Resserella which is the older genus. The large series of shells 
formerly assigned to Resserella are thus left without a name. I propose Pauci- 
crura to serve in this capacity and designate Orthis rogata Sardeson as type 
species of the genus. The familiar Silurian Parmorthis thus becomes Resserella 
and our Resserellas, which are numerous, become Paucicrura. 
