234 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
like ridges with their long axis arranged radially. Ridge with a long gentle slope 
on one side and a steep, precipitous face on the other, or a carina may occupy 
the middle of the elevation. Anterior side of the carina with a pit or gash, sepa- 
rating the elevation from the next anterior one. Asymmetrical elevations located 
mainly on sides of shell and with the long slope facing the lateral margin. 
Brachial interior: Platform low; septum low and short. 
Measurements in mm.— 
Length Width Thickness 
EIGHIOLU DS” Gees ce ore eee ce coe ons meee 21.7+ 19.0 8.4? 
Pafatype (zoogs2e)'t 20. OG AL Baer 27.5-+ 23.2 13.4? 
ff (ro9g40a)} ci. atith. 2e.P eirien: 28.6 25.2 11.8 
Types.—Holotype: 109353b; figured paratypes: 109352d,e, 109353a; un- 
figured paratypes: 109349a, 109352a-c,f,g. 
Horizon and locality—Bromide formation (Pooleville member-Oxoplecia 
gouldi zone) in Oklahoma: At Rock Crossing of Hickory Creek about center 
Bet s5. Pe GS) Re ee riner Fis, Warter’ County. 
Discussion ——This species differs from the two previously described species of 
this genus by its ornamentation and large size. The radial elevations of L. gale- 
nense are smaller and more distantly spaced than those of L. oklahomense. 
From L. schucherti the Oklahoma species is distinguished by the crowded 
concentric lines and absence of radial marking on the flanks. In L. schucherti 
the flanks are marked by crowded growth lines, and the radial elevations are 
more closely spaced. Furthermore, in L. schucherti the radial elevations are of 
different character from those of L. oklahomense, being more elongate at right 
angles to the radial direction and without the carina. 
LINGULASMA OCCIDENTALE Cooper, new species 
Plate 13, F, figures 13-17 
Shell thin, of about medium size for the genus; apical angle about 90° ; sides 
nearly parallel and straight ; anterolateral extremities narrowly rounded ; anterior 
margin very gently curved or nearly straight ; pedicle valve with nearly flat lateral 
profile; brachial valve with gently convex lateral profile; surface marked by 
fine, concentric, minutely wavy lines and radial lines of minute granules. 
Measurements in mm.—Holotype, length 18.4, width 16.2, thickness 6.2. 
Types.—Holotype: 116793b; figured paratypes: 116793a, 117955; unfigured 
paratype: 117956. 
Horizon and locality —Yellow limestone above 25-foot sandstone of Eureka 
group in Nevada: 3 miles north of Martin Ranch on southwest side of hill 8167, 
Monitor Range, Roberts Mountains (1°) Quadrangle. 
Discussion.—This species is suggestive of L. matutinum and L. compactum 
in the closely crowded concentric ornamentation but differs from both of the 
others in the greater degree of crowding and compaction of the ornamentation. 
