408 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
Interior: Pedicle muscle area with the diductor tracks extended anterior to 
the adductor track; pallial impressions not well developed. Brachial valve with 
stout cardinal process having a thick shaft and wide trilobed myophore. Central 
lobe of myophore with strongly elevated carina. 
Measurements in mm.— 
Brachial Hinge 
Length length Width width Thickness 
Holotype)... bees « 88 17.5 17.5 23.3 225 5.1 
Paratype (110208d).. 13.9 13.9 20.3 23.1 3.7 
y (110208e).. 11.3 10.7 16.5 21.5 3.1 
- (110216b).. 15.0 15.0 20.5 23.8 4.6 
Types—Holotype: 110208a; figured paratypes: 110208b,c,e, I102IIb,c, 
110212a,b ; unfigured paratypes : 110208d, 110211a; measured paratype: 110216b. 
Horizon and locality —Tulip Creek formation in Oklahoma: Beside road 14 
miles west of Nebo, SEASW3 sec. 22, T. 2 S., R. 3 E.; valley of West Spring 
Creek, 3 miles east of Pooleville, Murray County. 
Discussion.—This species attains a large size for the genus. In outline it 
varies considerably according to its age. In general the younger forms are much 
extended at the hinge, but the cardinal extremities of the older specimens are 
more nearly a right angle. Some young forms occur without alate extremities, 
a condition believed to be due to crowding in growth. This species resembles 
another large form occurring in the Whistle Creek formation of the Appalachians, 
V. austrina, but differs in possessing a flatter pedicle valve and shorter, less 
strongly developed fold and sulcus. 
VALCOUREA INTRACARINATA Ulrich and Cooper 
Plate 73, A, figures 1-4 
Valcourea ? intracarinata UtricH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 125, 
pl. 21C, figs. 9-12, 1938. 
When this species was originally described its assignment to Valcourea was 
questioned. At that time the strong carina on the median lobe of the cardinal 
process was not known to be a distinctive feature of the genus. This carina, as 
well shown herein, is a generic character in Marmor and later specimens, but 
absent from a group of post-Marmor shells formerly placed in Valcourea but 
now referred to Campylorthis. 
This species is especially distinguished by its small size, great width, strong 
median ridge inside the brachial valve, and the deep median sulcus. It is per- 
haps the earliest known species of the genus. 
Types.—Holotype: 92852f; paratypes: 92852a-e,g-i; additional specimens: 
110226. 
Horizon and locality—Upper part of Upper Pogonip group (Valcourea zone) 
in Nevada: In Ikes Canyon on the east side of the Toquima Range, Roberts 
Mountains (1°) Quadrangle. 
