PLATE L. - 



PAGE. 

 Figs. land 2 CAMEROCERAS PHOTEIFORME Hall 777 



(See also plates i,vm, MX, i.xi, i.xn. i 



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. 3 CAMEROCKRAS, sp 777 



Cast of a slender CoZpoceros-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. 



