Figs. 30 to 34 
30 to 32 
33 and 34 
Figs. 35 to 37 
35 and 36 
37 
Figs. 38 to 44 
38 
39 
40 
41 and 42 
43 
44 
Figs. 45 to 47 
45 
46 and 47 
LIOSPIRA OBTUSA “Us BUG |S ior. <i sic:c:2:c cis icrorniesete wioloiers atalavaiatelere eustelste ie emcieserte ciate eed 
Three views of a large specimen, chiefly a cast of the interior. showing the 
obtuse periphery and in figure 32 the great thickness of the shell in the 
umbilical region. The latter, however, seems never to have been completely 
filled, a small perforation occurring in every case. Stones River group, Dixon, 
Illinois. 
Profile and sectional views of a smaller specimen, the latter showing the 
umbilical perforation. Geological and Natural History Survey of Minnesota, 
Museum Register No. 687. 
LIOSPIR'A ANGUSTATA (U: @ndSy., %- SEES ger Bef. erases creole melanie e/eisil ners peteislarsione cleiores’sielee 
(See also plate LXIx.) 
Two views of a large specimen retaining considerable of the shell. Fusispira 
bed, Trenton group, Wykoff, Minnesota. 
Vertical section of a small specimen showing narrow umbilical perforation and 
rapidly increasing shell surrounding it; from same locality. 
LIOsPiRA PROGNE Billings) sp. =< - 2:32). d5s-cteeptem stabs hele ta bee: dal hearse cre soe oe eetetee 
Under side of a specimen from the Fusispira bed of the Trenton group at 
Wykoff, Minnesota. This specimen presents the usual appearance of the 
species as it occurs in Minnesota. Of the shell it retains only the concave 
solid filling of the umbilicus. 
Profile view in outline of a rather small silicified shell, showing the peripheral 
band. The sutures are very indistinct and the surface quite smooth. Lower 
division of the Stones River group, Murfreesboro, Tennessee. 
Vertical section of a typical specimen from the Trenton at Burgin, Kentucky. 
Basal and profile views of the solid axis of a large specimen. ‘Trenton group, 
Hartsville, Tennessee. 
Under side of another axis in which the callosity which fills the umbilicus is 
more distinctly outlined than usual. 
Another Tennessee specimen in which the umbilical cavity is unusually narrow. 
ETOSPLRASPE RS TMIETS pL ere cles cereus aiieharaceseete alone sie oie Ne Rael lem ctats an ote tear caste retcy-7atat ara 
Apical side of a specimen from the Trenton group at Hartsville, Tennessee. 
Basal and apertural views of another specimen from the same locality showing 
the greatly expanded umbilical callosity which distinguishes this species from 
L, helena Billings sp. 
997 
996 
998 
