58 



NEW YORK STATE MUSEUM 



Brachiopods 

 Trigeria lepida mut. pygmaea Loomis 

 Productella spinulicosta mut. pyg- 

 maea Loomis 

 Strophalosia truncata mut. pygrnaea 

 Loomis 



Tropidoleptus carinatus mut. pyg- 



niaeus Loomis 

 Ainbocoelia umboiiata mut. pluto 



Loomis 



A. umbonata mut. pygmaea Loomis 

 Nucleospira concinna mut. pygmaea 

 Loomis 



Cyrtina bamiltonensis mut. pyg- 

 maea Loomis 



Spirifer marcyi mut. pygmaeus 

 Loomis 



S. granulosus mut. pluto Clarke 

 S. tullius mut. belphegor Clarke 

 S. medialis mut. pygmaeus Loomis 

 S. mucronatus mut. becate Clarke 

 S. fimbriatus mut. pygmaeus Loomis 

 S. fimbriatus mut. simplicissimus 



Loomis 

 Crinoid stems 

 Pentremites leda Hall 



Genesee shale 



This shale carries only a sparse fauna and its fossils are not 

 well preserved. In the densely black layers there is rarely any- 

 thing to be obtained, but lignites sometimes of considerable 

 length, occasionally Lepidodendron and conodont teeth have also 

 been found herein. 



The less bituminous shales contain: 



Pleurotomaria rugulata Hall 

 Styliolina fissurella Hall 

 Pterocbaenia fragilis Hall 

 Lingula spatulata Hall 

 Orbiculoidea lodensis Hall 



Liorbyncbus quadricostatus Hall 

 Probeloceras lutberi Clarke (occa- 

 sionally) 

 Bactrites aciculum Hall 



Crenundewa limestone 



The fauna here appearing is, as we have explained on pre- 

 vious occasions, the first appearance in this district of the 

 Portage or Naples fauna of the beds overlying. It is thus a 

 prenuncial fauna announcing the invasion and occupancy of the 

 field by a congeries of species not before known in New York. 

 It is evident that this fauna came in from the west and covered 

 for a short time only, the whole area from here westward to 

 Lake Erie. We have shown elsewhere the probability that the 

 rock itself, which is largely composed of the pteropod Stylio- 

 lina, represents a deep water deposit of pteropod ooze and its 

 associated organisms are also those of deep water habit. The 

 fauna and Horn of this limestone are as follows and in this list the 



