710 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
ro mm. long about 20 costellae occupy a space of 5 mm. Interspaces marked by 
minute concentric fila. 
Pedicle valve very slightly convex in lateral profile and forming a low arch 
in anterior profile. Beak inconspicuous; umbo narrowly swollen and extending 
anteriorly as a low fold to about the middle. Valve gently swollen in the median 
portion, somewhat flattened at the anterior. Slopes to the lateral margins long 
and gentle. Interarea fully twice the length of the interarea of the brachial valve. 
Pseudodeltidium narrowly arched. 
Brachial valve gently concave in the posterior half and the greatest concavity 
is the narrow depression extending anteriorly from the umbo which corresponds 
to the fold of the pedicle valve. Anterior half flattened or very slightly concave. 
Anterolateral and lateral areas flattened to very slightly convex. Cardinal ex- 
tremities deflected slightly toward the pedicle valve. Interarea short, strongly 
hypercline. 
Interior of pedicle valve with widely divergent diductor scars and deeply im- 
pressed pallial trunks ; brachial valve with moderately elevated median ridge and 
small adductor field. Cardinal process with bulbous surface facing pedicle valve. 
Measurements in mm.— 
Brachial Hinge 
Length length Midwidth width Thickness 
Hypotype (110001!a).......... 12.0 10.5 13.9 14.4 1.5 
Me (TVOOSIB) HO PAs 10.0 9.0 12.1 13.2 1.8 
i (110896e)..3....... 8.1 7:3 9.3 10.0 1.5 
f (GIT SO 52) ete canes 8.3 7.6 10.7 10.9 2 
- (PEOSGED) obs cas sa 9.4 8.4 10.2 10.5 1.7 
Types——Holotype: M.C.Z. 8624; paratype: M.C.Z. 8625 ; figured hypotypes: 
T10895a,c, 1108g6a-d, 110g00a-f, 110901a,b; measured hypotypes: 1108q5b, 
1108Q6e. 
Horizon and locality.—Base of the Athens formation in Tennessee: At the L. 
and N. railroad station in Athens, Athens (T.V.A. 125-NE) Quadrangle; above 
the quarry, 600 feet S. 40° E. of the railroad crossing 1 mile northeast of the 
courthouse in Athens, Athens (T.V.A. 125-NE) Quadrangle; Craighead Creek, 
4 mile north of Christiansburg, Sweetwater (T.V.A. 131-SW) Quadrangle; 
road along Meadow Fork just east of its junction with the valley road, 24 miles 
northeast of Calhoun, Calhoun (T.V.A. 125-SW) Quadrangle; just southeast 
of the intersection of the valley road and the road up Crouth Hollow, 24 miles 
south-southeast of Riceville, Calhoun (T.V.A. 125-SW) Quadrangle. 
Discussion.—This species was first described as a Rafinesquina, but the simple 
cardinal process, the stout shell, and the form of the pedicle muscles are all un- 
like that genus. Apatomorpha is closest to Palaeostrophomena and may be con- 
sidered as having the same relationship to that genus as Strophomena has to 
Rafinesquina. No other species of Apatomorpha is now known to which A. pul- 
chella may be compared. None of the described brachiopods from Girvan, Scot- 
land, appear to belong to Apatomorpha. 
