INDEX 



Morphologic terms in descriptions and specific compari- 

 sons are omitted. Numbers in bold face refer to primary 

 descriptions, definitions, or explanations. 



Abyssothyris Thomson, 7 



Actinoconchus M'Coy, 11 



Adductor marks, 20, 21 



Adductor muscle, 15, 18, 19 (fig. 1), 



20, 21, 34 

 Adjustor muscle, 21 

 Alaska, 64, 65, 66, 67, 68, 69, 110, 111 

 Alpena Limestone, 45, 47, 60, 61 

 Arkansas, 117, 119 

 Artinskian, 65, 70 

 Asia, 64, 65, 91 

 Athyridae, 11 

 Athyris M'Coy, 11 

 Atriboniidae, atriboniid, 1, 8, 11, 13, 23, 



26, 28, 29, 30, (fig. 3), 36, 37, 77, 91 

 Atriboniinae, 29, 30 (fig. 3), 31, 36, 37 

 Atribonium n. gen., 2, 4, 5, 8, 12, 13, 14, 

 15, 16, 26, 29, 30 (fig. 3), 31, 34, 35, 

 36, 37, 39, 78, 79, 96, 97, 98, 122, 129, 

 130 

 bisinuatum (Rowley), 121, 122 

 cooperorum n. sp., 13, 42, 45, 46 



(fig. 7), 55, 62, pi. 2 

 gainesi (Nettelroth), 54 

 gregeri (Branson), 39, 43, 48, 49 

 (fig. 8), 50 (fig. 9), 55, 58, 61, 

 62, pi. 3 

 halli (Fagerstrom), 43, 47, 52, 55, 



61,62 

 illinoisensis (Cooper), 43, 61, 62 

 kemahani (Whiteaves), 43, 53, 61, 



62, pi. 3 

 pauperum (Belanski), 43, 55, 62, 



pi. 3 

 pingue n. sp., 40, 43, 47, 55, 57, 59 



(fig. 10), pi. 2 

 rhomboidale (of Fagerstrom), 43, 



47 

 rostratum n. sp., 40, 55, 60, 62, pi. 3 

 savagei (Cooper), 43, 61, 62 



simatum n. sp., 38, 40, 42 (fig. 4.5), 

 44 (fig. 6), 47, 55, 58,61, 62, pi. 1 

 succiduum n. sp., 40, 43, 54, 61, 62, 

 pi. 2 



A try pa Dalman, 11 



Barnett Formation, 103, 104 



Bell Shale, 42, 46, 47 



Billingsellid, 17 



Bolivia, 146 



Bone Spring Limestone, 149 



Brachymimulns Cockerell, 7 



Brazer Formation, 108 



Britain, British, 85, 146 



Burlington Limestone, 163 



Buttress plates (lateral), 32, 51, 153, 

 157, 158, 159 



Callaway Limestone, 48, 51, 52 



Camarophorella Hall and Clarke, 162, 

 163 

 mutabilis Hyde, 163 



Camarophoria King, 3, 14, 18, 33, 79, 

 90, 138, 142, 161 

 antisella Broili, 82, 83, pi. 7 

 bitingi Grabau, 97, 98, 162 

 cestriensis Snider, 97, 105, pi. 12 

 crassa Hamlet, 97, 111, pi. 18 

 deloi King, 147 



hamburgensis Weller, 73, pi. 4 

 hueconiana Girty, 147, pi. 19 

 indcntata de Koninck, 97 

 karpinskii Tschernyschev, 90 

 netschajezvi Tschernyschev, 90, 92 

 nora Belanski, 40 

 obesa Clark, 40, 97, 121, pi. 16 

 parvula Tschernyschev, 90, 92 

 paupera Belanski, 40, 55, pi. 3 

 pentameroides Tschernyschev, 64, 



65,79 

 pcntatingi Grabau, 97, 98 

 pcrplexa Belanski, 40 

 planodorsata Belanski, 40 



i8 7 



