560 NEW YORK STATE MUSEUM 



Protocycloceras lamarcki Billings (sp.) 



Page 441 

 See pi. IS, fig. 1-5 



1 A Specimen retaining the surface sculpture 



2 Enlargement (x3) of a portion of the sculpture of the same 



specimen to show the alternation of striae 

 The original is from the Fort Cassin beds at Fort Cassin and now. 

 in the New York State Museum. 



Protocycloceras (?) cf. furtivum Billings (sp.) 



Page 445 



3 A fragment showing the oblique direction of the annulations 



Drawn from a gutta-percha squeeze 

 The original is from the Beekmantown beds at the Spelman ledge 



near Beekmantown N. Y. and now in the New York State 



Museum. 





i 



Spyroceras clintoni Miller (sp.) 



Page 445 

 See pi. 14, fig. 4 



4 Natural section of a fragment, showing the curvature of the conch 



and the depth of the cameras and of the septas. The siphuncle 

 is shown in the lower part 



5 Natural section of a fragment showing the position of the si- 



phuncle and the oblique direction of its inflations 



6 Surface sculpture of a fragment. Faint alternating longitudinal 



lines are not brought out in the drawing 



7 Apical part of a conch 



The originals of figures 4, 6, 7 are from the dove-colored Chazy 

 limestone near Little Monty bay ; that of figure 5 is from the 

 middle Chazy beds of the west shore of Valcour island. All are 

 now in the New York State Museum. 



