580 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
Measurements in mm.— 
Brachial 
Length length Width Thickness 
Fiypotype. A LITISZR) os 6. wept. «ne Bre? 10.8 13.0 8.0 
ie (TITTEA). Sgeee. ae 13.7 12.5 14.0 9.6 ? 
o (BUDUSHOR 235 cap iie ay 14.2 13.3 15.4 9.5 
Types.—Figured hypotypes: 111155b, 111156a, 111157a,c, 118011a; measured 
hypotype: I11157b. 
Horizon and locality.—Lincolnshire formation (Hogskin member) in Ten- 
nessee: 2.1 miles southwest of Mount Eager Church, Hogskin Valley, Powder 
Springs (T.V.A. 154-SW) Quadrangle ; Sally Cleveland Farm, ¢ mile southwest 
of Washburn, Dutch Valley (T.V.A. 154-SE) Quadrangle; Evans Ferry; 3 mile 
east-northeast of Red Hill, 4 miles west-southwest of Thorn Hill, Avondale 
(T.V.A. 162-SW) Quadrangle. 
Lincolnshire formation in Tennessee: Near Marble Bluff, 8 miles west-north- 
west of Loudon, Loudon (30’) Quadrangle. 
Discussion—Some forms of this species very closely resemble C. bicostata 
but differ therefrom in the presence of the minute granules, more numerous costae 
on the flanks, and the fact that the costae extend farther posteriorly toward the 
beak than in C. bicostata, in which the posterior half of the shell is generally 
smooth. 
Willard originally referred this shell to Camarotoechia, and the presence of the 
granules are suggestive of some of the species originally called Camarotoechia 
in the Ordovician. Granules are present in some species of Rostricellula but are 
rare or hitherto unnoticed on members of the genus Camerella. In fact C. quad- 
riplicata is the only Camerella noticed in this book which has granules. 
CAMERELLA TENNESSEENSIS Cooper, new species 
Plate 115, D, figures 22-31 
Shell small with length and width about equal; outline subtriangular ; apical 
angle 100° ; sides rounded; anterior truncated ; anterior commissure broadly and 
gently uniplicate. Posterior half smooth, anterior half costate, 5 costae in the 
sulcus, 6 on the fold, and 5 on the flanks. 
Pedicle valve gently convex in lateral profile and with the maximum con- 
vexity in the median region ; anterior profile gently convex in the median region 
but the sides dropping steeply and abruptly ; umbonal and median regions swol- 
len ; sulcus originating slightly anterior to the middle, wide and shallow. Tongue 
short and broadly rounded. Flanks narrowly rounded. Beak short, lying an- 
terior to the brachial umbo. 
Brachial valve moderately convex in the median region but with strongly 
curved umbo and anterior ; strongly convex in anterior view and with precipitous 
sides. Median and umbonal regions swollen; fold slightly elevated; flanks nar- 
rowly rounded. 
Measurements in mm.—Holotype, length 7.6, brachial length 7.9, width 7.9, 
hinge width 2.8, thickness 6.1. 
