PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 935 
Measurements in mm.— 
Brachial Hinge 
Length length Width width Thickness 
PIO NEV DG. sn ieissicvana siciaborre svaching 14.6 14.6 17.8 20.7 23 
Paratype s( 2177102). «jos 05 0m. 95 12.3 12.0 15.6 ? 4.0 
" CEL77I7O) 3c forts ote 11.4 Tr2 16.6 18.0 2.5 
ss CPEFIIFA) Pere eee ts 12.8 12.5 18.2 19.8 ? 4.4 
i GI FENG. SE LR 15.4 15.3 an2 24.0 5.0 
Types.—Holotype: 117718; figured paratypes: 117715, 117716a, 117717a-c, 
117719a,c; unfigured paratypes: 117716b, 117717d,e, 117719b. 
Horizon and locality—Bromide formation (Pooleville member-O-xoplecia 
gouldi zone) in Oklahoma: At Rock Crossing of Hickory Creek, about center 
sec. 35, T. 5 S., R. 1 E., Carter County; Pooleville member, basal cobbly beds, 
Spring Creek, sec. 17, T. 2 S., R. 1 W., Murray County; just west of road on 
Russell Ranch, SE# sec. 3, T. 2 S., R. 3 E., Murray County. 
Discussion.—This species is characterized by its small size, short and wide 
pedicle muscle area, the cancellated pattern on the outside of the valves, and its 
generally great width. Strophomena trentonensis Winchell and Schuchert is 
the one described species most suggestive of S. crinerensis, but it differs in its 
more nearly quadrate form, nearly rectangular cardinal extremities, and gen- 
erally larger size. 
STROPHOMENA DELICATULA Fenton 
Strophomena delicatula FENton, Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 155, pl. 9, 
figs. 4-6, 1928. 
Types—Holotype: Walker Mus. 25537; paratype: Walker Mus. 33400; 
figured specimen: Walker Mus. 25538. 
Horizon and locality—Barnhart formation in Missouri: 24 miles west of 
Ste. Genevieve, Weingarten (15’) Quadrangle. 
STROPHOMENA DIGNATA Fenton 
Strophomena dignata FENton, Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 151, pl. 10, figs. 3-5, 
1928, 
Types.—Holotype: Walker Mus. 25532; paratypes: Walker Mus. 25533, 
25535- 
Horizon and locality.—Barnhart formation in Missouri: 24 miles west of 
Ste. Genevieve, Weingarten (15’) Quadrangle. 
STROPHOMENA EXIGUA Fenton 
Strophomena exigua Fenton, Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 152, pl. 10, fig. 6, 
1928. 
Type.—Holotype: Walker Mus. 25956. 
Horizon and locality—Upper part of Plattin group (Macy formation) in 
Missouri: South Beckett Hill, Weingarten (15’) Quadrangle. 
