PLATE XLIX. 



PAGE. 



Fig. 1 CAMEROCERAS, sp 777 



A long cylindrical sipho, with very broad septal funnels; representing a distinct 

 but otherwise unknown species. 

 From the Trenton limestone, Cannon Falls, Minn. 



This specimen may be advantageously compared with the figures of Orthoeeras 

 simpsoni Billings, given by Whiteaves. (Orthoceratidas of the Trenton lime- 

 stone of the Winnipeg basin; Trans. Boy. Soc. Canada, vol. ix, sect, iv, p. 80, 

 pi. vii, flgs. 2, 2a, 3; pi. viii, fig. 1, 1891). 



Fig. 2 CAMEROCERAS PHOTKIFOBME Hall 777 



(See also plates i.vm, xi XLI, XLII.) 



A portion of a large individual, showing the extent of the solid apical end of the 

 sipho, and the abrupt increase in the depth of the air-chambers above the distal 

 extremity of the body. Where the apical sheath is broken, at the lower 

 extremity of the specimen the cast of the internal cavity and the thickness of 

 the sipho are exposed. Cannon Falls, Minn. 



