GASTROPODA. 981 
Lophospira ampla.] 
umbilicus. The first convexity beneath the peripheral band represents the lower 
carina of L. perangulata and other species, and in young shells it is sharp enough to 
be called a carina, but as growth proceeds it becomes more and more obtuse. 
Aperture straight at the inner margin, and somewhat narrowly produced at the 
lower angle, Surface markings rarely preserved; whenever preserved they consist 
of rather distant, delicate, sublamellose striz, with very fine lines between them, all 
curving backward strongly to the peripheral band. 
This is a much larger shell than L. perangulata, yet has about the same number 
of volutions. The apical angle also is greater, while both the under and upper sides 
of the volutions are obviously different in several respects. J. centralis never has 
so strong a subsutural swelling, its peripheral band is less prominent, and the under 
side of the whorls more ventricose. 
Formation and locality.—Rare in the Stones River group at High Bridge, Kentucky; not uncommon 
in the Black River group, especially in the Ctenodonta bed, at St. Paul, Minneapolis, Cannon Falls, 
Chatfield and Fountain, in Minnesota; also in Mercer county, Kentucky. Asyetit is not known to occur 
in the Trenton proper, but a smaller yet otherwise indistinguisbable form reappears in the Utica group at 
Cincinnati, Ohio, and localities in that vicinity. About 60 specimens. 
Collections.—Geological and Natural History Survey of Minnesota; H. O. Ulrich; W. H. Scofield. 
Museum Register, Nos. 7521, 6865. 
LopHosPrrRA AMPLA, 7. sp. (Ulrich.) 
PLATE LXXIII, FIGS. 52-54, 
Hight, of Loraine group specimens, 20 to 32 mm., of Richmond group specimens, 
22 to 50 mm.; apical angle 70° to 80°. Volutions about six, the last equalling about 
two-thirds of the total hight. Upper carina thick, near the suture, present on all 
volutions; lower carina nearly obsolete, represented by a broad swelling or low” 
ridge, above which to the prominent peripheral band the surface is more or less 
concave. Inner lip very thick, almost or entirely covering the minute umbilicus, 
very broad and turned obliquely downward and forward in the basal half. Surface 
markings very strongly curved, unequal, on the whole not sharply defined. 
Closely related to L. oweni, yet easily distinguished by the greatly thickened, 
broad and obliquely extended inner lip. The apical angle also is greater, and the 
lines of growth are more curved, especially at the base, while the upper carina does 
not fade away on the last volutions as in that species. The presence of this carina 
distinguishes it from the associated and otherwise similar L. multigruma Miller. 
LL. medialis, which is usually much smaller, with the same number of volutions, a 
smaller apical angle and more distinct umbilicus, also has no such sutural carina. 
Formation and locality.—Cincinnati period, Lorraine group, Cincinnati, Ohio, and Covington, Ken- 
tucky; Richmond group, Richmond, Indiana, and at several localities in Boyle and Lincoln counties, 
Kentucky. i 
Collection .—E. O. Ulrich. (17 specimens.) 
