PLATE LIIlI. 
Higssed fo) 3: CAMEROCERAS WE NNIEPING: 7 SDajitl Ovatenielaievetsincsis) etalnie slain cieledeleteolstastateiolsve! tetera reteisietele rele aie 
(See also plate wir.) 
1 Longitudinal section of a small fragment through the sipho; showing a portion 
of the thick continuous wall of the tube and the annulations formed at the 
junction therewith of the septa. On one side the siphonal wall is but partially 
retained. 
2 and 3 Two views of the Same specimen. 
Fig. AN ORTHOGERAS sUESUE URI, | SPs: TO Vis nets cps icicsels opoysteiee sietetere ee eeraierel etait) clay reval stelnietev-felaistetiets 
(See also plates, XGVIE and Ly.) 
A portion of a shell protruding from an internal cast of the siphon of Cameroceras 
proteiforme. Erom the Trenton limestone at Cannon Falls, Minn. 
Fig. 5 CAMEROCERAS PROTEIFORME) Halle cise nese cieteeins secs ms fcodoMTaCOD A GyOGae 
(See also plates XLVIII, XLIX, L, LI.) 
Longitudinal section of a siphonal cast enclosing two individuals of Orthoceras 
or Clinoceras. Trenton limestone, Cannon Falls, Minn. 
779 
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