CANANDAIGUA AXD NAPLES QUADRANGLES 



57 



tated, were so unfavorable that the organisms were able to 

 advance but a little in the line of species development and yet 

 they a^jparently acquired the power pf reproduction and mani- 

 fested themselves in these arrested conditions probably for 

 several generations. These fossils were studied by the writer 

 some years ago, and have been more exhaustively examined of 

 late by Dr F. B. Loomis from material c«ollected all along the 

 line of outcrop of the layer. 



The specimens are to be extracted from the rock only with 

 great labor but it is to be expected that forms present at 

 one place will appear at others and hence the entire list of the 

 known species is here appended. It will be observed that the 

 c^.esiguations used in Dr Loomis's list here given indicate muta- 

 tions only from the types of Hamilton species and not deep seated 

 sjjecific differences. 



Crustaceans 

 Bejrichia dagon Clarke 

 EntxMnis prosepbiiia Loomis 

 Cryphaeus boothi var. calliteles 



Green 



Ceijhalopods 

 Bactrites (sp.) ? mut. parvus Loomis 

 B. (sp.) mut. pygmaeus Loomis 

 Orthoceras nuntium Hall 

 O. sciutilla (?) mut. mephisto Clarke 

 O. subulatum mut. pygmaeuin 



Loomis 

 Tornoceras uniangulare mut. astarte 



Clarke 

 T. uniangnlare Conrad 



Pteropods 

 Tentaculites bellulus? mut. stebos 



Clarke 

 T. gracilistriatus mut. asmodeus 



Clarke 



Gastropods 

 Loxonema delphicola jnut. moloch 



Clarke 

 rieurotomaria 



P. itys mwf. pygmaea Loomis 

 r. capillaria mut. pygmaea Loomis 



MacTochilina bamiltoniae mut. pyg- 

 maea Loomis 

 M. hebe mut. pygmaea Loomis 

 Diaphorostoma lineatum mut. belial 

 Clarke 



Lamellihranchs 



Conocardium eboraceum mut. pyg- 



maeum Loomis 

 Buchiola retrostriata mut. pygmaea 



Loomis 

 Grammysia constricta mut. pygmaea 



Loomis , 



Paracyclas lirata mut. pygmaea 



Lootnis 

 Palaeoneilo constricta mut. pygiuaea 



Loomis 

 P. plana mut. pygmaea Loomis 

 Leda rostellata mut. pygmaea 



Loomis 

 Nuculites oblongatus mut. pygmaeus 



Loom is 

 N. triqueter mut. pygmaeus Loomis 

 Nucula varicosa mut. pygmaea 



Loom is 

 N. corbuliformis inut. pygipaea 



Loomis 

 N. lirata mut. pygmaea Loomis 



