74 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
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(2, 3) Posterior and dorsal views of a specimen preserving both valves, 
1, holotype, U.S.N.M. 125339. Locality U.O. 2201-2. 
(4, 5) Anterior and ventral views of a young specimen, X I, paratype, 
U.S.N.M. 125342. Locality S103. 
(6) Plasticine replica of the exterior of a brachial valve, X 1, para- 
type, U.S.N.M. 125345. Locality L8. 
(7-9) Respectively ventral, side, and anterior views of a large pedicle 
valve showing strong geniculation, X 1, paratype, U.S.N.M. 125337. 
Locality Pro. 
(10-12) Respectively ventral, side, and anterior views of another pedicle 
valve showing scar of large anterior spine (in fig. 12), 1, para- 
type, U.S.N.M. 125343. Locality S46. 
(13) Posterior view of another pedicle valve showing deep median 
sulcus, X I, paratype, U.S.N.M. 125338. Locality U.O. 2204-3. 
B. Marginifera? multicostellata Cooper, new SpecieS...........eeeee neers 
(14-17) Respectively side, ventral, anterior, and posterior views of the 
holotype showing reticulate visceral disk region, 1, U.S.N.M. 
125365. Locality S46. 
C. Antiquatonia sulcata Cooper, new Species........22.0csccescensssacrs 
(18-21) Respectively posterior, anterior, side, and ventral views of the 
holotype, showing deep sulcus, & 1, U.S.N.M. 125327. Locality S51. 
(22) Impression of the exterior of a brachial valve showing reticulate 
visceral region and prominent depression (shown as a fold) around 
the ear, 1, paratype, U.S.N.M. 125329. Locality S43. 
PLATE 6 
A. Anidanthus minor Cooper, New SPeCieS........... cee eee cece rec ceeces 
(1-4) Respectively ventral, anterior, posterior, and side views of broad 
but crushed specimen, 1, paratype, U.S.N.M. 125351. Locality S87. 
(5-7) Respectively side, posterior, and ventral views of nasute speci- 
men, X I, paratype, U.S.N.M. 125360. Locality S46. 
(8, 9) Side and posterior views, X 2, showing the wide hinge and ears, 
paratype U.S.N.M. 125535. Locality S103. 
(10-12) Respectively posterior, ventral, and side views of a large, broad 
specimen, < 1, holotype U.S.N.M. 125361; (13, 14) side and ventral 
views of the holotype, 2, showing costellae. Locality U.O. 2201-1. 
(15) Posterior of another pedicle valve showing beak and ears, X 2, 
paratype, U.S.N.M. 125534. Locality L8. 
(16, 17) Respectively X 1 and X 2 enlargements of an impression of 
the exterior of a brachial valve showing concentric lamellae, para- 
type, U.S.N.M. 125466. Locality U.O. 2207-2. 
B. Marginifera? profundosulcata Cooper, new SpecieS........... eee eee eee 
(18-21) Respectively ventral, posterior, anterior, and side views of 
the holotype showing the wide and deep sulcus, x1, U.S.N.M. 
125364a. Locality S49. 
C. Marginifera? costellata Cooper, new SPeCieS.........ceeeeeeeceeeeeees 
(22-25) Respectively ventral, anterior, posterior, and side views, X 1, 
of the holotype, U.S.N.M. 125368. Locality S46. 
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