7i2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
PAUCICOSTELLA CANADENSIS Cooper, new species 
Plate 172, A, figures 1-6; plate 173, D, figure 24 
Wider than long, cardinal extremities nearly a right angle or acute; sides 
nearly straight or sloping toward the middle; anterior margin broadly rounded ; 
surface costellate, large costellae numbering 8 or 10 on each side of the median 
line and appearing in 2 generations; fine costellae covering entire surface, 6 
or 7 in I mm. at the front margin. 
Pedicle valve unevenly convex, with the convexity strongest at the umbo, the 
median region somewhat flattened and the anterior part depressed toward the 
brachial valve; anterior profile broadly and slightly convex. Umbo somewhat 
narrowly swollen but not extended far forward. Median region flattened to con- 
cave ; anterior quarter or third depressed to form a shallow, wide sulcus. Flanks 
bounding sulcus flattened. 
Brachial valve nearly flat in lateral profile ; same in anterior profile ; umbo con- 
cave, the concavity short and shallow ; median region slightly inflated, the swell- 
ing produced to the anterior margin to form a barely perceptible, broad fold; 
flanks bounding fold flattened. 
Measurements in mm.— 
Brachial Hinge 
Length length Midwidth width Thickness 
Holotype (pedicle valve) .......... 8.0 ? 11.9 11.7 ? 
Paratype ( “ NE TzZO8E) ... 7.8 ? 13.4 13a ? 
. Guia Me) LEPROSE) «ain OL ? 10.7 11.0 fe 
. (brachial valve 1173905d).. ? 7.6 12.6 12.5 ? 
oH (Guia oe TET QOSE iach 7.5 10.1 11.9 ? 
iH Ts Hl LEA ZOSM ier. o.-18 8.1 II.0 11.9 ? 
it Ci, uit ‘SnivTr7sorg) sug. 7.0 Tr3 ? I.I 
Types.—Holotype: 117395b; figured paratypes: 117395a,c-f, 117394b; un- 
figured paratypes: 117394a, 117395g-w. 
Horizon and locality—Boulder in Mystic conglomerate in Quebec, Canada: 
In Range 6, Lot 21, 2.6 miles north and 4 mile east of Mystic, Stanbridge Town- 
ship; Range 6, Lot 20, same township. 
Table Head series (upper) in Newfoundland: At Table Point Cove. 
Discussion.—No other species of this genus is known to which this one can 
be compared. 
GLYPTAMBONITES Cooper, new genus 
(Greek glyptos, engraved; ambon, umbo) 
Suggesting Rafinesquina sensu stricto in outline and profiles. Pedicle valve 
gently convex in lateral profile, brachial valve flat or very slightly concave. Shells 
of large size. Surface marked by a few strong costellae in a field of very fine 
costellae, strong oblique wrinkles marking the shell just below the posterior mar- 
gin and on each side of the beak. 
Pedicle valve with teeth small and simple, like those of the orthids; dental 
plates short, produced forward as a low ridge on the outside of the muscle field, 
