BRACHIOPODA. 



39 



S. Leidyi, Norwood and Pratten, St. Louis group. 

 (S. Leidyi, var. Meramecensis, 



Swallow, Warsaw limestone. 



S Leidyi,yar. Chester ensis. Swallow, Chester limestone. 

 S. increbescens. Hall, Chester limestone. 



S. increbescens, var. Americanus, 



Swallow, Chester limestone. 



S. increbescens, var. transversalis, 



Hall, 

 S. opimus, Hall, 

 S. acuticostatus, De Koninck, 

 S. annectans, Walcott. 

 /. Divaricatus-type : 

 S. divaricatus, Hall, 



Chester limestone. 

 Coal Measures. 

 Coal Measures. 

 Carboniferous. 



Corniferous and Hamilton groups. 



V, OSTIOLATi: 



S. perextensiis, Meek and Worthen, Corniferous limestone 



S. macrothyris, Hall, 



S. Manni, Hall, 



S. angustus. Hall, 



S. Marcyi, Hall, 



S. audaculus, Conrad. 



S. Macconathi, Nettelroth, 



S. formosus. Hall, 



S. ligus, Owen, 



S. Wortheni, Hall, 



S. granulosus, Conrad, 



S. fornax, Hall, 



S. eurytines, Owen, 



S. eurytines, var. fornaculus, Hall, Hamilton group. 



S. Parryanus, Hall, Hamilton group. 



S. asper. Hall, Hamilton group. 



S. Macbridii, Calvin, Hamilton group. 



S. Pluto, Clarke, Genesee shales. 



S. neglectus, Hall, Keokuk group. 



S. plenus. Hall, Burlington limestone. 



a. S. acuminatus. Hall, Corniferous and Hamilton groups, 



Corniferous limestone. 



Corniferous limestone. 



Corniferous and Hamilton groups. 



Hamilton group. 



Hamilton group. 



Hamilton group. 



Hamilton group. 



Hamilton group. 



Hamilton group. 



Hamilton group. 



Hamilton group. 



Hamilton group. 



