New Missouri Fossils. — Roivley. • 269 
a Burlington spirifer The area is not entirely confined to 
the pedicel valve. The aperture is a high, narrow triangle. 
The cardinal extremities are almost acute. 
The plications are distinct but low and almost flat, orna- 
mented by fine, crowded cross lines, recalling the ornamen- 
tation of Spirifer pennatus (S. mucronatus of Conrad). 
This beautiful spirifer occurs sparingly at the top of the 
4th division of the Lower Burlington limestone at Louisia- 
na, Mo., associated with Agaricocrinus planoconvexus and 
Granatocrinus aplatus. 
Spirifer carinatus (nov. sp.). 
Plate V, Figs. 4 and 5. Cardinal and front views, natural size. 
Fig. 6. Brachial valve X /4. 
Length of the shell a little more than half the width. 
About 24 plications either side of the sinus and a like 
number either side of the mesial fold. 
The sinus is extravagantly excavated at the front into a 
deep V and is traversed b}' ten plications, some of which 
bifurcate before reaching the front. The beak of the pedi- 
cel valve incurved but not strongly. The cardinal line is 
hardly the full length of the shell. The cardinal area is 
confined to the pedicel valve, is moderately high and with 
parallel sides except near the extremities. The aperture is 
a low, broad triangle. 
The brachial valve appears much narrowerat the middle, 
from the high, keeled mesial fold. The valves are crossed 
by a few lines of growth, but are apparently without orna- 
mentation. The plications are mostly bifurcating ones and 
with a slight tendency toward grouping. 
This handsome shell comes from the fifth and top di\'is- 
ion of the Lower Burlington limestone at Louisiana, Mo., 
and is rather rare. 
Zaphrentis radicula (nov. sp.). 
Plate \", Figs. 7 and 8. Side and calyx views, natural size. 
Corallum simple, irregular!)- turbinate, made irregular 
by constrictions in growth. 
Radicular spines over the outer surface, but irregularly 
distributed. Otherwise the surface appears without orna- 
mentation. The cup but partly free from the matrix. AlDout 
