552 



NEW YORK STATE MUSEUM 



Orthoceras modestum sp. nov. 



Page 456 



1 A natural section showing the siphuncle and the depth of the 



cameras 



2 Specimen retaining a cast of the living chamber and one camera. 



Shows the size of the living chamber, its anterior contraction, 

 the depth of the septa and of the cameras 



3 A living chamber with part of the outer wall, which is not con- 



stricted 



The original of figure 1 is from the upper Chazy (C 6 ) of the 

 neighborhood of Chazy ; those of figures 2 and 3 are from the 

 dove-colored Chazy limestone (Q) of the east shore of Valcour 

 island. They are now in the Xew York State Museum. 



Geisonoceras shumardi Billings (sp.) 



Page 437 



4 A natural section showing the siphuncle and cameras 



The original is from the middle Chazy (B 2 ) of the neighborhood 

 of Chazy X. Y., and now in the Xew York State Museum. 



Orthoceras progressum sp. nov. 



Page 4i4 



5, 6 Two views of the type ; the former showing the rate of growth 

 and the sutures ; the latter, in a section, the siphuncle, the depth 

 of the cameras and of the septa 

 The original is from the dove-colored upper Chazy limestone on 

 the east shore of Valcour island, and now in the New York State 

 Museum. 



