PLATE L. 
Bigs; j/and! 2) (CAMEROGERAS WPR OMEN O RMS EM aN Sore epee eta relatolatesnretclolelateyotet= a ste lo eminiela tele loia melo teria ta ees TIT 
(See also plates LVIII, LIX, LXI, LXII.) 
1 Cross-section of the continuous apical sheath (E) in the filling (e) of which are 
three small orthoceran shells (x). Trenton limestone, Cannon Falls, Minn. 
2 Fragment of a large internal cast with the filling of the air-chambers embracing 
the cast of the continuous apical sheath. Cannon Falls, Minn. 
Fig. BY TOUT olor NSH oS compose sudHnon cngaSetooony qusocS Caan obasedancuasaeceanoe seoc05 117 
Cast of a slender Colpoceras-like sipho, with broad septal funnels and a narrow 
acuminate extremity which may indicate the filling of the endosiphon. From 
the Trenton limestone, probably at Cannon Falls, Minn. 
