BRACHIOPODA. 



37 



S. octocostatus, Hall, 



S. arrectus, Hall, 



S..tribulis, Hall, 



S. hemicydics. Meek and Worth en, 



S. duodenarius. Hall, 



b. LsBvis-type. 



S. bicostatus, Vanuxem, 



S. bicostatus, var. petilus. Hall, 



S. modestus. Hall, 

 (?) S. nympha, Billings, 



S. CanandaiguaB, sp. nov., 

 (?) S. urbanus, Calvin, 



Lower Helderberg group. 

 Oriskany sandstone. 

 Oriskany sandstone. 

 Oriskany sandstone. 

 Corniferous limestone. 



Niagara group. 

 Niagara group. 

 Lower Helderberg group. 

 Lower Helderberg group. 

 Hamilton group. 

 Hamilton group. 

 Portage group. 



S. laevis. Hall, 



2. Duplicispinei = Reticularia, McCoy, 1844: 



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



ton groups. 

 S. subundiferus. Meek and Worthen, Hamilton Group. 



(?) S. praematurus. Hall, 



S. hirtus. White and Whitfield, 



S. pseudolineatus. Hall, 



S." setigerus. Hall, 



S. clarus. Swallow, 



S. lineatus, Martin, 



S. perplexus, McChesney, 



IV. Aperturati : 



a. Disjunctus-type: 

 S. arenosus. Hall, 

 S. unicus, Hall, 

 S. Whitneyi, Hall, 



Chemung group. 

 Choteau limestone. 

 Kinderhook-Keokuk groups. 

 St. Louis-Chester groups. 

 Chester limestone. 

 Coal Measures. 

 Coal Measures. 



Oriskany sandstone. 

 Corniferous limestone. 

 Upper Devonian. 

 Chemung group. 



S. disjunctus, Sowerby, 



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



S. Billingsanus, Miller, Devonian. 



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

 S. praemonens, sp. nov., Niagara group. 



S. Hungerfordi, Hall, Upper Devonian. 



