BRACHIOPODA. 



37 



S. octocostatus, Hall, Lower Helderberg group. 



S. arrectus, Hall, Oriskany sandstone. 



S..tribulis, Hall, Oriskany sandstone. 



S. hemicydus. Meek and Worthen, Oriskany sandstone. 



S. duodenarius, Hall, 



b. Laevis-type. 



S. bicostatus, Vanuxem, 



S. bicostatus, var. petilus, Hall, 



S. modestus. Hall, 

 (?) S. nyvipha, Billings, 



S. Canandaiguse, sp. nov., 

 (?) S. urbanus, Calvin, 



S. Isevis, Hall, 



Duplicispinei ^Reticularia, McCoy, 1844: 



S. fimbriatus, Conrad, Oriskany, Corniferous and Hamil- 



ton groups. 

 S. subundiferus. Meek and Worthen, Hamilton Group. 



Corniferous limestone. 



Niagara group. 

 Niagara group. 

 Lower Helderberg group. 

 Lower Helderberg group. 

 Hamilton group. 

 Hamilton group. 

 Portage group. 



IV. 



(?) S. praematurus, Hall, 



S. hirtus, White and Whitfield, 



S. pseudolineatus. Hall, 



S; setigerus. Hall, 



S. clarus, Swallow, 



S. lineatus, Martin, 



S. perplexus, McChesney, 



Aperturati : 



a. Disjunctus-type : 

 S. arenosus, Hall, 

 S. unicus. Hall, 

 S. Whitneyi, Hall, 

 S. disjunctus, Sowerby, 



Chemung group. 

 Choteau limestone. 

 Kinderhook-Keokuk groups. 

 St. Louis-Chester groups. 

 Chester limestone. 

 Coal Measures. 

 Coal Measures. 



Oriskany sandstone. 

 Corniferous limestone. 

 Upper Devonian. 

 Chemung grouj). 



S. disjunctus, var sulcifer, var. nov. Chemung group. 

 S. BilUngsanus, Miller, Devonian. 



L Hungerfordi-type. = Choristites, Fisher, 1825: 

 S. prsemonens, sp. nov., Niagara group. 



S. Hungerfordi, Hall, Upper Devonian. 



