838 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
DACTYLOGONIA sp. 2 
Plate 219, H, figure 15 
Two specimens were taken from the rotted Botetourt material at the junction 
of Virginia Highways 731 and 724 about 2 miles northwest of Brownsburg, 
Lexington (15’) Quadrangle. These specimens show the muscle field to per- 
fection. No dental plates are preserved in either specimen. The diductor scars 
are elongate and somewhat tear shaped. The adjustor scars appear outside the 
diductors. They are shorter than the diductors and are also tear shaped. The 
diductor scars extended directly anteriorly. The adductor scars are small and 
narrowly elongate and separated by a slight median ridge. 
Figured specimen.—117607A. 
DACTYLOGONIA sp. 3 
Plate 217, E, figures 8-10 
This small Dactylogonia is most suggestive of D. parva but differs in having a 
shorter trail and a somewhat less geniculated anterior and in not having the 
prominent ridge at the place of geniculation. This may be the young of some 
larger species, but the early geniculation suggests a small adult. 
Figured specimen.—117608. 
Horizon and locality.—Benbolt formation in Virginia: West of Rye Cove, 
Clinchport (T.V.A. 188-NW) Quadrangle. 
DACTYLOGONIA sp. 4 
Plate 194, D, figures 23-27 
Small, wider than long. Pedicle valve with visceral region gently convex in 
lateral profile and with an angle of geniculation of about 115°. Point of genicu- 
lation about 6 mm. anterior to the beak. Trail rounded, short. Surface marked 
by prominent, somewhat irregular concentric lines cancellated by fine radial lines. 
Larger costellae obscure. Brachial valve gently concave. 
Measurements in mm.—1176090, length 8.9, brachial length 7.6, midwidth 
I1.1+, hinge width 11.3+, thickness 1.4, surface length 10.5, trail length 3.5. 
Figured specimen.—117609. 
Horizon and locality.—Sevier formation in Tennessee: + mile northeast of 
Miser, Louisville (T.V.A. 138-SE) Quadrangle. 
Discussion.—This species is suggestive of D. concentrica and is marked some- 
what like it, but the brachial valve is more deeply concave and the trail is longer. 
DACTYLOGONIA sp. 5 
Plate 217, I, figures 23-26 
This is an unusually well preserved specimen, but its form and lack of conspicu- 
ous geniculation suggest that it is the young of a larger species not yet known. 
The specimen is wider than long, with a gently convex pedicle valve and a moder- 
ately concave brachial valve. The ornamentation consists of fairly regular distant 
