72 [Assembly 



Original Names. Changed Names, Remarks, etc. 



Vol.1, page 



Natica 1 42 This is probably a species of Holopea. 



Nucula 1 donaciformis 316 Tellinomya donaciformis. 



" levata 150 Tellinomya levata. 



" ? pOStriata 151,201 Genus undetermined. 



Ogygia 1 vetusta 227 Asaphus vetustus. 



Olenus asaphoides 256 



" undulostriatus 258 



Oncoceras ._ 196 



Oncoceras constrictum 197 



Ophileta 11 



Ophileta complanata 11 



" levata.. 11 



Orbicula coelata 290 Trematis ccelata. 



" 1 CraSSa 290 Genus? 



" 1 deformata 23 Genus ? 



" 7 filosa ._ 99 Crania? filosa. 



The relations of this species are with 

 Crania, if it be not a true Crania. 



" lamellosa 99 Discina lamellosa. 



" '' Subtruncata 290 Probably related to Crania, from its 



^^^j^^^ ^.^j^ other forms in the higher 

 rocks. 



" terminalis 100 Trematis terminalis. 



Ormoceras gracile 58 



U tenuifillim 55 222 ■'■^^^ species is probably identical with 



' Ormoceras backi. 



" var. distans 58 



Ortliis sequivalvis 120 



" bellarugosa 118 



" centrilineata 289 



" costalis 20 



" dichotoma 125 



" disparilis 119 



" 1 erratica 228 



" fissicosta 121 



" insculpta 125 



" OCCidentalis 127 TMs species, wOhO. sinuata and O. 



subjugata, may form but a single species ; though from the collections in my 

 hands in 1847, I found what appeared to be satisfactory means of distinguish- 

 ing them. Since examining the species of the Lower Helderberg limestone, I 

 have found numerous forms which appear as closely allied as do these, but 

 which are nevertheless clearly distinguished by their interior markings. I 

 am not satisfied that the European species, Orthis porcata, is identical 

 with ours. 



" pectinella 123 



" var. semiovalis 124 



" perveta 120 



