NO. 12 PERMIAN BRACHIOPODS FROM OREGON—COOPER 57 
Brachial valve at least one-quarter the length shorter than the ven- 
tral valve, moderately convex in lateral profile but carinate in an- 
terior profile. Fold strongly elevated, angular in section but bearing 
a narrow groove down the center. Flanks flattened and with long 
oblique slopes to the margins. 
Measurements in mm.—Hypotype, U.S.N.M. 125400, length 26.9, 
width 22.3, thickness 17.8, length of brachial valve 20; U.S.N.M. 
125406, length 34, length of brachial valve 21.9, width at middle 29+, 
thickness 23.5. 
Types.—Figured hypotypes, U.S.N.M. 125400, 125401, 125402, 
125404, 125406. 
Localities—614, 638, 639; L8, L23; P10; S4, S12, S4o, S46, S47, 
S49, S50, S51, S56, S68, S87, S103; U.O. 2201-4, 2202-2, 2204-3, 
2205-5, 2207, 2210. 
Discussion.—None of the specimens of this species from Oregon 
is well preserved, but all appear to be typical of the Russian species. 
SPIRIFERELLA PARVA Cooper, new species 
Plate 11A, figures 1-5 
Shell small for the genus, elongate-oval in outline; sides nearly 
parallel; cardinal extremities probably produced into small ears; sur- 
face fascicostellate. 
Pedicle valve strongly convex in lateral profile with strongly in- 
curved beak; umbonal and curved portion of valve approximating 
one-third the shell ; sulcus originating at the beak, widening gradually 
anteriorly to occupy about half the width at the front; anterior pro- 
duced into a long, sharply pointed tongue. Flanks rounded and with 
very steep sides. Surface marked by 5 fascicles of about 3 costellae; 
sulcus marked by numerous radial costellae. Deltidium prominent. 
Brachial valve moderately convex with the maximum convexity 
located slightly posterior to the middle; carinate in anterior profile; 
fold originating at the beak, high and narrow, marked by slight 
median depression. Flanks convex and steep-sided. 
Measurements in mm.—Holotype, length 22.7, width 14.9(?), 
thickness 17.0, length of brachial valve 16.3. 
Type.—Holotype, U.S.N.M. 125405. 
Locality—U.O. 2204-3. 
Discussion—This species is characterized by its laterally com- 
pressed form and narrow fold. It is a small species, smaller than 
S. draschei (Toula). It differs from the latter by its narrower form, 
more incurved beak of the pedicle valve, strongly elevated and ex- 
