PLATE LIX. 
igs: Tito 28 CYR TOCERAS eMINNEAPOGIS, SPs O Viste aeleralonssisiclelereoielasiiete leis =)clelarere elaielate iets retaaistevoeys 808 
1,2 4 Lateral, dorsal and ventral views of a small specimen retaining the shell and 
3 preserving the apertural margin. 
5, 6 Ventral and lateral views of another small example with the aperture entire. 
7,8 Lateral and ventral views of a larger specimen which is a partial internal cast; 
showing faint revolving bands interrupting the concentric striw, and the 
position of the sipho. 
7a Outline of aseptum. From the Trenton shales at Minneapolis. 
’ 
Migs! =.9) ibor 11 MCyRTOOERAS ISOC OMEELDIGGS Ps MOV ese elelete oicte evel=ele e]eleleenivinistalolejeretatere lt feletatelala are teintaleieistere 810 
Dorsal, ventral and lateral views of the typical specimen. From the Trenton 
horizon at Janesville, Wisconsin. 
higseiZetoSs CyRTOONRAS HOUGHTON ISD MOV: seiciscreeric crete eleciereyinsierleleleretetsie re ielete cee tele eae ouegsrelets 807 
12 Lateral view of an internal cast of large size. 
13, 14, 15 Lateral and ventral views of ap average specimen. 
14a Outline of aseptum, showing the position of tbe sipho and the great lateral 
compression of the conch. From tbe Trenton limestone, Cannon Falls, Minn. 
Migse6. = 60. CYRTOONRAS .CORNIO Dia UM MEDAN E rere teroycersieielsle ts a(staieleinle <\eeirieferer= isl e)eYoterelsieteterieielersiateiaerets 809 
16 Side view of a specimen, showing the form and curvature. 
16a Transverse section. Galena shales, Warsaw. 
IGS eli bom) Cxi2 LOCH RASS NIE EUS etme lll feleiaclefelerafolntnsele)statelalalol=ceralalelele ere icle eleteietels otet=leleleteleencieiiers neetets 804 
17, 18, 19 Lateral, dorsal and ventral views of a specimen having the body-chamber nearly 
entire, and showing the nearly gyroceran curvature, the closely set septa and 
the position of the sipho. 
17a Outline of aseptum at the point of greatest curvature of the conch. From the 
Galena limestone at Wykoff, Minn. 
20 Lateral view of a less complete specimen. In the Trenton at Beloit, Wisconsin. 
