MEDINAN, NIAGARAN, AND CHESTER FOSSILS 83 
mm. in width, has a thickness of about 0.5 ^mm., is distinctly 
outlined along its convexly curved margin, and presents a steep 
slope on its concavely curved side, facing the umbilicus. No 
trace of surface markings is visible. Therefore it is impossible 
to determine the generic relations of this species. The fact that 
the callous deposit is strongly margined along its exterior border 
suggests that this shell may be genericall}^ distinct from Liospira. 
Locality and formation.^ — Quarry ^ mile northeast of Center- 
ville, Ohio, in the argillaceous strata immediately beneath the 
Brassfield limestone. Possibly a Pycnomphalus. 
Lophospira ehlersi Sp. nov. 
Plate XIV fig. 17 
Shell 17.5 mm. in height, with a maximum width of 15.5 
mm., and an apical angle of about 80°. At the aperture the last 
volution has an elevation of 10 mm. There are 5 or 6 volutions, 
the apical one rarely being preserved distinctly. General 
outline simdar to that of Lophospira peracuta Ulrich and Scofield^^ 
but with a much lower spire, somewhat as in Lophospira tropi- 
dophora Meek. The upper volutions expose only their upper 
slopes and the peripheral angle, but the second last volution 
exposes an increasing amount of its lower slope, so that near the 
aperture fully 2 mm. intervene between the peripheral angle of 
the second last volution and the suture beneath. The peripheral 
angle is more or less acute, the degree of acuteness usually being 
greater along the last volution. The slit-band is located on 
the peripheral angle. At the aperture its width is about 1 mm. 
or slightly more. Its upper and lower margins are defined 
distinctly by very fine, sharp lines. The entire width of the 
band is raised into an angular ridge, whose upper and lower 
faces form an angle of about 60°. The upper face of the slit- 
band slopes at about the same angle as the upper face of the 
volution, and the lower face of the band slopes at an angle simi- 
lar to that of the lower face of the volution, the crest of the 
ridge formed by the band being directed upward and outward. 
Idem., pi. 73. 
