BRACHIOPODA. 
37 
S. octocostatus, Hall, 
S. arrectus, Hall, 
S. tribulis. Hall, 
<S. hemicyclus. Meek andWorthen, 
S. duodenarius. Hall, 
Lower Helderberg group. 
Oriskany sandstone. 
Oriskany sandstone. 
Oriskany sandstone. 
Corniferous limestone. 
h. Laevis-type. 
S. bicostatus, Vanuxem, 
S. bicostatus, var. petilus. Hall, 
S. modestus. Hall, 
(?) S. nympha, Billings, 
S. Canandaiguae, sp. nov., 
(?) S. urbanus, Calvin, 
S. laevis. Hall, 
Niagara group. 
Niagara group. 
Lower Helderberg group. 
Lower Helderberg group. 
Hamilton group. 
Hamilton group. 
Portage group. 
2 . 
Duplicispinei = Reticularia, McCoy, 
S. fimbriatus, Conrad, 
S. subundiferus. Meek and Worthen 
(?) S. praematurus. Hall, 
S. hirtus. White and Whitfield, 
S. pseudolineatus. Hall, 
S.‘ setigerus. Hall, 
S. clarus. Swallow, 
S. lineatus, Martin, 
S. perplexus, McChesney, 
Oriskany, Corniferous and Hamil¬ 
ton groups. 
Hamilton Group. 
Chemung group. 
Choteau limestone. 
Kinderhook-Keokuk groups. 
St. Louis-Chester groups. 
Chester limestone. 
Coal Measures. 
Coal Measures. 
IV. Aperturati: 
a. Disjunctus-type; 
S. arenosus, Hall, 
S. unicus, Hall, 
S. Whitneyi, Hall, 
S. disjunctus, Sowerby, 
S. disjunctus, var sulcifer, var. nov. 
S. Billingsams, Miller, 
Oriskany sandstone. 
Corniferous limestone. 
Upper Devonian. 
Chemung group. 
Chemung group. 
Devonian. 
1. Hungerfordi-type. = Choristites, Fisher, 1825: 
S. praemonens, sp. nov., Niagara group. 
S. Hungerfordi, Hall, Upper Devonian. 
