552 NEW YORK STATE MUSEUM 



Orthoceras modestum sp. nov. 



Page 436 



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



cameras 



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



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

 the depth of the septa and of the cameras 



3 A Hving chamber with part of the outer waH, which is not con- 



stricted 

 The original of figure i is from the upper Chazy (Cg) of the 

 neighborhood of Chaz}'; those of figures 2 and 3 are from the 

 doA^e-colored Chazy limestone (C^) of the east shore of Valcour 

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



Geisonoceras shumardi Billings (sp.) 



Page 437 ; I 



4 A natural section showing the siphuncle and cameras 



The original is from the middle Chazy (Bg) of the neighborhood 

 of Chazy N. Y., and now in the New York State Museum. 



Orthoceras progressum sp. nov. 



Page 4j4 



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. 



