750 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
just anterior to it; umbo concave; area just anterior to posterior margin form- 
ing a more or less deep groove extending to the cardinal extremities. Interarea 
moderately long, hypercline. Interior with strong, erect cardinal process, strong 
median ridge, and elevated visceral disk with margins overhanging geniculated 
area; pallial marks impressed on geniculated area. 
Measurements in mm.— 
Brachial Surface Mid- Hinge Thick- 
Length length length width width ness Height 
FLOMGEV IIE voles ce pues g 8s 66 8.1 6.6 10.5 9.9 10.8 2.6 3.9 
Paratype (117447a)..... 78 6.4 10.5 9.6 10.7 27 3.9 
fe (117447b)..... 8.2 6.9 11.0 10.0 10.6 2.5 ag 
Types.—Holotype: 117447¢ ; figured paratypes: 117447b,e,f,h, 117449a,¢c,d,f,g, 
117450a, 117451a; unfigured paratypes: 117447a,c,d,i, 117448, 117449b,e, 
117450b, 117451b,c. 
Horizon and locality—Chatham Hill formation in Virginia: 1.2 miles S. 31° 
E. of Sharon Springs, Burkes Garden (15’) Quadrangle; Grayson Farm, 4 miles 
southwest of Bland, Bland County. 
Benbolt formation (base) in Virginia: West side of hill east of Cedar Point 
School, Hilton (T.V.A. 197-NE) Quadrangle; 0.2 mile south of middle fork 
of Moccasin Creek, 14 miles due south of Hansonville, Hansonville (T.V.A. 
205-SW) Quadrangle. 
Edinburg formation (Cyrtonotella zone) in Virginia: Ravine on south side 
railroad tracks, mile east of Strasburg Junction, Strasburg (15’) Quadrangle; 
(?) 14 miles north of Double Toll Gate, Winchester (15’) Quadrangle. 
Discussion.—This species is characterized by its ragged exterior produced by 
patches of lamellae of considerable size adhering to the shell. The species is of 
moderate size and fairly transverse. It is not so large nor so convex as L. ab- 
breviata but is more convex than L. incompta which it resembles in its ragged 
exterior. Leptellina sublamellosa is like some of the younger forms of L. deli- 
catula but does not attain the rectangular outline nor does it develop the long 
interarea as on the pedicle valve of the Alabama species. 
LEPTELLINA TENNESSEENSIS Ulrich and Cooper 
Plate 187, C, figures 9-13; plate 187, D, figures 14-30; plate 188, A, figures I-11; 
plate 189, B, figures 24-29; plate 190, D, figures 26-31 
Leptellina tennesseensis ULRicH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 626, 1936; 
Geol. Soc. Amer. Special Pap. 13, p. 192, pl. 39A, figs. 1, 2, 4, 5, 1938. 
Plectambonites delicatulus RAyMoND (not Butts), Bull. Mus. Comp. Zool., Harvard Coll., 
vol. 68, No. 6, p. 207, pl. 3, fig. 11, 1928. 
Shell large, variable, varying from wider than long to having the length and 
width about equal. Cardinal extremities acute and generally auriculate. Lateral 
margins nearly straight or oblique and generally rounded in old specimens. 
Front margin broadly to narrowly rounded, occasionally somewhat nasute. Sur- 
face multicostellate ; young valves marked by 5 narrow but strong primary cos- 
tellae that extend to the beak. As the shell grows, costellae of a size intermediate 
