732 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
Lincolnshire formation (Hogskin member) in Tennessee: On Sally Cleveland 
Farm, $ mile southwest of Washburn Station, Dutch Valley (T.V.A. 154-SE) 
Quadrangle; at the bend of the road, Red Hill, 44 miles west-southwest of Thorn 
Hill, Avondale (T.V.A. 162-SW) Quadrangle; on U. S. Highway 25E just 
south of the first bridge north of Thorn Hill, Avondale (T.V.A. 162-SW) Quad- 
rangle; 2 miles southwest of Hall Crossroad, Fountain City (T.V.A. 146-SW) 
Quadrangle; south side of the school at Chesney, Luttrell (T.V.A. 155-NW) 
Quadrangle; 1 mile southeast of Washburn, Dutch Valley (T.V.A. 154-SE) 
Quadrangle; in Maloneyville, John Sevier (T.V.A. 146-SE) Quadrangle; Lee 
Valley, Lee Valley (T.V.A. 171-NW) Quadrangle; Clinchport, Clinchport 
(T.V.A. 188-NW) Quadrangle. 
Discussion.—This is a very variable species as described herein. It is possible 
that more extensive collections will indicate further separations of geographi- 
cally restricted forms, but the available collections will permit no such splitting. 
This species is characterized by its large size, generally alate cardinal extremi- 
ties, at least in youthful forms, and the strong but not extravagant development 
of internal features. This species is smaller and usually more convex than S. gil- 
dersleevei and larger and less convex than S. subnasutus. The species is most 
like S. lamellosus but differs in having less transverse shells and generally more 
acute cardinal extremities. Some variants of each species resemble each other, 
but the majority of specimens of each species indicate the more transverse form 
and more rectangular outline of the western species. 
Numerous specimens of Sowerbyites occur in the Hogskin shale and in thin, 
argillaceous limestones associated with the shale. These Hogskin forms are often 
more transverse than some of the specimens etched from Lincolnshire limestone. 
These, however, appear to be end members of the species. These wide forms 
are generally more acuminate on the cardinal extremities than S. lamellosus. 
They are also linked to the somewhat narrower limestone specimens by inter- 
mediate forms. 
SOWERBYITES sp. 1 
Of considerable interest in the stratigraphic and geographic distribution of 
this genus is its presence in the Quebec City formation. A single pedicle valve 
obtained from Dr. R. Bureau, Laval University, Quebec, indicates the species 
represented to be similar to S. triseptatus but not so transverse and somewhat 
rectangular on the cardinal extremities. In lateral profile the greatest convexity 
is at about the middle and the anterior slope is long and steep, its length about 
equal to that of the body of the shell. The angle of geniculation is about 100°. 
Measurements in mm.—123300, length 14.4, surface length 17.0, midwidth 
22.7, hinge width 23+, height 4.4. 
Described specimen.—123300. 
Horizon and locality. Quebec City formation (Mountain Hill conglomerate) 
in Quebec, Canada: 400 to 500 feet south of Morin Building, Mountain Hill, 
Quebec City. 
