470 New York State Museum 



Hydrozoan colonies, 174, 175 

 Hyoliths, 230 



Igneous rocks, 62, 208 



definition, 15 



relative age, 72 



structures in, 71 

 Inclined strata, 50 

 Inclusions, 63 

 Incrusting plants, 96 

 Incrusting shells, 176 

 Indian Ladder beds, 292 

 Induration, 22 

 Insects, 423, 436, 441 

 Interformational sheet, 63 

 Intrusive igneous rocks, 63 

 Intrusive sheet, 63 

 Inwood limestone, 210 

 Irish Moss, 134 

 Iron oxides, 23 



Irondequoit limestone, 328, 331 

 Isoclinal anticlines, 53 

 Isopods, 163 

 Ithaca fauna, 405 

 Ithaca shale member, 403 



Jellyfishes, 83, 86, 108, 121, 145, 172, 174, 230 



milky-cross, 145 



milky-disk, 145 



rainbow jelly, 177 



speckled, 145 



sun jelly or sea blubber, 145 

 Jingle Shells, 112, 122, 158, 168, 172, 175, 176 

 Johnstone, J., cited, 182, 449 

 Joints, 53, 72 

 Juniata formation, 319 

 Jurassic period, 432 



Kalkberg limestone, 373 

 Karnes, 28 



