Netv Missotiri Fossils. — Rozvley. 267 
incurved, perforate. Both valves are ornamented by numer- 
ous crowded, fine, radiating striae. 
Probably this is the earliest species of the genus, collect- 
ed from the soft chert of the Lower Burlington limestone 
at Louisiana, Mo., and in the author's collection. A much 
larger shell of the same genus, poorly preserved, but show- 
ing the spirals where a portion of the test is broken awa}', is 
apparently of the same species. 
The only other species described from the Burlington 
limestone, Dr. White's Acambona prima, is widely different 
from the present species. 
Grammysia ? imbricata (nov. sp.). 
Plate V, Figs. 60, 61. Right valve toward the observer; same more 
obliquely, natural size. Fig. 62, enlarged view to show surface orna- 
mentation. 
Shell small, subovate, widest in front. Length nearh- twice 
the width. Valves convex. Beak subanterior, prominent. 
Surface marked by eight or nine strong concentric terrace- 
like striae; otherwise ornamented by beautiful zig-zag lines 
that to the eye have a peculiar cloth-like texture. Of the 
four or five specimens in the collection, from the onl)- one 
having both valves in place, unfortunateh' the test has been 
removed. The specimen figured is the largest one \'et found, 
two others being less than half as large. Collected at Lou- 
isiana, Mo., from the soft cherts of the Lower Burlington 
limestone. 
Conocardium spinalatum (nov. sp.). 
Plate V, Figs. 54, 55, 56. Left side, cardinal and posterior views of 
the largest specimen, natural size. 
Shell, small (somewhat spirifer-form), ovate, subtrigo- 
nal \entricose. Cardinal length much greater than the dis- 
tance across the valves. Posterior more rounded than is 
usually seen in this genus. The tubular extension at the pos- 
terior end preserved a short distance but broken. When 
entire was probably of great length. Beaks posterior to the 
center, incurved. Valves marked by rather sharp radii be- 
tween which the interspaces are marked by numerous fine 
concentric striae. The collection contains four specimens. 
