268 The American Geologist. May, loou 
the largest of which is here figured. Collected from the soft 
cherts of the Lower Burlington limestone at Louisiana, Mo. 
Macrochilina tantilla (nov. sp.). 
Plate V, Figs. 57, 58. Views, natural size of the only two specimens 
in the collection. 
Shell turreted, elongate; length twice the width. Vol- 
utions six or more. Upper one minute. Lower one occu- 
pies more than half the height of the shell. Aperture sub- 
oval. Lines of growth indistinct. Specimens collected at 
Louisiana from the soft cherts of the Lower Burlington lime- 
stone. 
Macrochilina l<eyesi (nov.sp.). 
Plate V, Figs. 65, 66. Views of the two specimens from which the 
description is made out, natural size. 
Shell turreted, subfusiform. Length twice the diameter. 
Volutions 8 to 10, the lowest occup^nng more than half the 
length of the shell. Upper ones minute. Aperture not ob- 
served as both specimens lie upon that side in the matrix. 
Surface marked by fine lines of growth. The only two spec- 
imens in the collection are imbedded upon the same small 
piece of soft white chert. Lower Burlington limestone, 
Louisiana, Mo. 
Specific name in honor of Prof. Charles R. Keyes, late of 
the Geological Survey of Iowa and late State Geologist of 
Missouri. 
Spirifer insculpius (nov. sp.). 
Plate V, Fig. i, 2, 3. Cardinal, front and side views of one of the 
types, natural size. 
The width of this shell is more than three times the 
length. About 20 plications, either side of the mesial fold. 
All simple throughout. The fold itself is rather narrow and 
but little elevated, having four or five plications 
The beak of the pedicel valve is scarcely incurved, hard- 
ly more so than that of the brachial valve. The sinus is 
narrow and not deep, with four or five plications. 
The cardinal area is a broad low triangle, the width be- 
ing about fi\-e times the height and yet it is a high area for 
