PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 269 
Measurements in mm.— 
Length Width Thickness 
Holotype, (pedicle valve)... ¢ sr.0s0's cee ose 11.0 9.6 1.5 
Paratype (brachial valve 109681b) ......... 14.2 14.1-+ ? 
“ Gib aft He MEOGOSIG)* Lav cshas 12.5 10.7 re 
Types—Holotype: 1o968ic; figured paratypes: 71891a, 109678, 109680, 
109681a,d; unfigured paratypes: 71891b-d, 109679a,b, 109681b,e,f ; figured speci- 
men: 109688. 
Horizon and locality—Bromide formation (Pooleville member-O-roplecia 
gouldi zone) in Oklahoma: At Rock Crossing of Hickory Creek about center 
Sec. 45; 1-5 3:, Rv E., Criner Hills, Carter County ; (zone 5), Spring Creek, 
N$ sec. 17, T. 2 S., R. 1 W., Murray County. 
Bromide formation (Mountain Lake member) in Oklahoma: Brownish granu- 
lar beds, Rock Crossing, as above. 
Discussion.—This species is fairly common in the Criner Hills and is charac- 
terized by moderate size and very long spines. In these respects it differs from 
S. canadensis (Ami) which is a large species, and also from S. dodgei in which 
the spines are reported as only 2 mm. in length. The pedicle umbo is faintly 
radiate as in S. subradiatum, but the latter is a much smaller shell with a more 
convex pedicle valve and different anterior ornamentation. 
SCHIZAMBON SUBRADIATUM Cooper, new species 
Plate 14, B, figures 12-19 
Shell of about average size for the genus, a little wider than long. Apical angle 
about 110°. Lateral margins of adults strongly rounded; anterior margin more 
gently rounded. 
Pedicle valve oval; faintly convex in the posterior half but becoming flat and 
very gently concave in the anterior portion. Length of pedicle track about one- 
third the length of the valve. Beak pointed; posterior slope steep. Region about 
the pedicle track and foramen marked by elevated, closely spaced, somewhat 
wavy concentric lines. A few obscure radial lines extending from the beak to 
a point opposite or a little anterior to the foramen. Spine-bearing lamellae closely 
spaced. 
Brachial valve subcircular in outline with both profiles moderately convex. 
Sulcus narrow and deep at the point of its origin at the beak, widening very 
gradually to the middle of the valve and becoming merged into the flattened an- 
terior third. Posterior third with distant and subdued concentric lines and a 
few spine bases. Beak and umbo smooth. Lamellae distant; spines numerous, 
about 1.5 mm. in length. 
Measurements in mm.— 
Length Width Thickness 
Holotype (pedicle valve) ..............0.005- 9.4 8.6 ? 
Paratype (pedicle valve 109685a)............. 8.8 77 1.8 
id (brachial valve 109686a) ........... ye 7.9 ? 
