818 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
convex profile and a long nonrugose trail. None have yet been found. Speci- 
mens of P. ? matura without the trail should be distinguishable from P. vir- 
giniensis by the length of the rugae. 
PTYCHOGLYPTUS VIRGINIENSIS Willard 
Plate 173, A, figures 1-7; plate 173, B, figures 8-12; plate 174, A, figures I, 2; plate 174, B, 
figures 3, 4; plate 174, D, figure 7; plate 174, E, figures 8-17; plate 186, H, figures 32, 33; 
plate 186, I, figure 34; plate 213, C, figure 22; plate 268, D, figures 12-15 
Ptychoglyptus virginiensis WiLLaRpD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, 
p. 283, pl. 2, fig. 12, 1928. 
Playfairia ? pulchra Butts, Alabama Geol. Surv., Special Rep. 14, p. 102, pl. 19, fig. 15, 1926. 
Ptychoglyptus pulchrus (Butts) WItLarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, 
No. 6, p. 284, 1928. 
Shell of moderate size, somewhat semicircular in outline; width about twice 
the length; hinge forming widest part; cardinal extremities subalate to mucro- 
nate. Lateral margins gently convex, oblique; anterior margin broadly rounded. 
Surface beautifully sculptured, variable, consisting of costellae of 2 sizes and 
short transverse wrinkles. The largest costellae appear in 3 generations, a 
median strong costella extending from beak to margin and as many as 9 strong 
costellae appearing on each side of the median one. Spaces between large cos- 
tellae occupied by as many as 12 fine costellae. Wrinkles generally confined to 
the spaces between large costellae except in the cardinal region. Rugae gen- 
erally short and arcuate posteriorly, chevron shaped. 
Pedicle valve very slightly convex in lateral profile, with a narrow but low 
median fold extending from the umbo to the front margin. Slopes of fold gentle 
and concave. Lateral extremities flattened. Anterolateral portions of shell some- 
what flattened. Beak pointed, prominent, narrow, and only slightly protruding 
posterior to the posterior margin. Interarea apsacline. Interior as described 
under the generic definition. 
Brachial valve gently concave in profile with area of greatest concavity form- 
ing a shallow trough from the beak to the margin. Lateral areas bounding sulcus 
nearly flat. Interarea anacline. Beak obsolete, marked by a pit, so strong is the 
bending of the interarea. Interior as described under the generic heading. 
Measurements in mm.— 
Brachial Hinge 
Length length Midwidth width 
FLOM fH shi. Rl. c ciealete ckhoteateins 9.1 ? 15.4 20.7 
Fiypoty pe (OS237) cies lesa Rove 8.2 ? 11.8 15.0 
oi GUTIOS 7A)! sh Gena. same 8.6 ? 13.3 16.0-++ 
ie (upT0s6a)),. .i..cactews II.2 10.6 16.2 18.8-+ 
ff (FRAT SD sce saeheee cuba. 5.6 ? 9.0 10.4+ 
Types—Holotype: M.C.Z. 8626; paratype: M.C.Z. 8627; figured hypotypes: 
98231a,a-1,b,b-1, I11042a-c, 111052, 111056, 117397, 117398a-f, 123285b,d,e,f ; 
holotype of P. pulchrus Butts: 71475; measured hypotypes: 111056a, I11057a. 
Horizon and locality—Effna-Rich Valley formations in Virginia: At Porter- 
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quad- 
