ig2 



NEW YORK STATE MUSEUM 



Monomerella walmstedti, 41. 

 Monroe county, dolomites, 9, 17-20. 

 Munier-Chalmas, cited, 59. 

 Murchisonia, 5, 74, 118, 119, 125, 135. 



billingsana, 127. 



hercyna, 127. 



hespelerensis, 72. 



laphami, 133. 



loganii, 65, 67, 124, 127. 



longispira, 127. 



macrospira, 65, 66, 127, 132, 133. 



mylitta, 125, 127. 



terebralis, 137. 



vitellia, 67. 

 Murie, cited, 38. 

 Murray, observations, 7. 

 Myalina mytiliformis, 49. 

 Mytilarca, 47-49. 



acutirostrum, 48-49, no. 

 explanation of plate, 150. 



eduliformis, 47, no. 



explanation of plate, 150 



foerstei, 49. 



mytiliformis, 49. 

 Mytilus edulis, 47. 



sigillum, 47. 



Natica, 119. 



Nerinea, 119, 120. 



Newberry, cited, 132. 



Niagara county, limestone and dolomite, 



13-16. 



Niagara dolomite, 7. 

 Nicholson, cited, 31, 32, 34, 37, 38, 40. 

 Niosch, investigations of, 119. 

 Norton, W. H., cited, 129. 

 Nucleospira, 128. 



Obolus conradi, 132, 133. 

 Oehlert, cited, 59, 67. 

 Ohio, Guelph fossils in, 131-34. 

 Oncoceras, 94, 95. 



Ontario, dolomites, 4, 20-22. 

 Oppel, investigations of, 119. 

 Oriostoma, 59. 



Orleans county, dolomites, 9-11, 17. 

 Orthis elegantula, 41. 



hybrida, 42. 

 Orthoceras, 77-81. 



abnorme, 133. 



angulatum, 78, 85. 



annulatum, 83. 

 var. americanum, 81, 82. 



bartonense, 21, 83. 



cadmus, 82, 86. 



cancellatum, 86. 



colnmnare, 78. 



crebescens, 78, 79, 80-81, in. 

 explanation of plate, 162, 164. 



darwini, 84, 85. 



laeve, 6. 



laphami, 82. 



medullare, 82, 86. 



nodocostatum, 82, 83. 



rectum, 78-79, in. 



explanation of plate, 167. 



scammoni, 77, 78. 



selwyni, 77, 78. 



trusitum, 11, 77-78, in, 137. 

 explanation of plate, 162, 168. 



undulatum, 82. 



virgatum, 82. 



virgatum ( ?), 86. 

 Orthothetes subplanus, 10, 21. 

 Orton, Edward, cited, 132, 133, 134. 

 Ostracoda, 106-7. 



Pecten, 119. 

 Peismoceras, 105. 

 Pentamerus, 117. 



mysius var. crassicosta, 130. 



oblongus, 123, 125, 133. 



occidentalis, 114, 122, 123, 124, 128, 131, 

 132. 



