INDEX. 



817 



A crotreta seebachi, described 710 



compared with Acjotreta carinaia 680 



AcrotTeta circularis 680 



general geographic and stratigraphic distribution tabu- 

 lated 106 



type specimen figured PI. LXXVII, fig. 3 



skantuTigcnsis, described 710 



general geographic and stratigraphic distribution tabu- 

 lated 106 



type specimen figured PI. LXIX, figs. 5, 5a-b 



sigrmlis, described 711 



general geographic and stratigraphic distribution tabu- 

 lated 106 



type specimen figured PI. LXIX.flg. 4 



"sipo," discussed 679 



socialu, described 711 



association mentioned 340 



compared with Acrotreta cariTiata 680 



Acrotreta schinalenseei 709 



Acrotreta seebachi 710 



Acrotreta sp. undt 715 



discussed 703 



lalse area in, discussed 674 



general geographic and stratigraphic distribution tabu- 

 lated 106 



type specimen figured PI. LXXIII, figs. 3 and 3a 



sociaiis Gronwall, discussed 712 



socialis Linnarsson, compared with Acrotreta socially von 



Seebach 709 



discussed 712 



sociaiis von Seebach, compared with Acrotreta sociaiis Linn- 



arsson 709 



ct. sociaiis Matley, discussed 703 



cf. sociaiis Matthew, discussed 712 



spinosa, described 713 



general geographic and stratigraphic distribution tabu- 

 lated 106 



surface ornamentation discussed 302, 672 



type specimen figured PI. LXXIX, fig. 4b 



subconica, described 713 



compared with Acrotkele coriacea 642 



Acrotreta gemma 685 



Acrotreta schmalenseei 709 



Acrotreta sociaiis 712 



false area in, discussed 674 



general geographic and stratigraphic distribution tabu- 

 lated 106 



interior unknown 673 



type of ^ crotreta 673 



type specimen figured PI. LXXIII, figs. 2f and 2g 



ulricki, described 714 



general geographic and stratigraphic distribution tabu- 

 lated 106 



type specimen figured PI. LXXVIIT, fig. 3 



uplandica, described 714 



general geographic and stratigraphic distribution tabu- 

 lated 106 



type specimen figured PI. LXX, figs. 3, 3a-b 



uplandica limbensis, described 714 



compared with Acrotreta uplandica 715 



general geographic and stratigraphic distribution tabu- 

 lated ,... 106 



type specimen figured PI. LXX, figs. 4, 4a-b 



sp. imdt., described 715 



discussed ■ 712-713 



general geographic and stratigraphic distribution tabu- 

 lated 106 



type specimen not figured. 



sp. undt. Westerg3,rd, described 715 



general geographic and stratigraphic distribution tabu- 

 lated 106 



type specimen not figured. 



Acrotretacea, classification of 321, 324 



distribution in Cambrian strata 316 



genera and species referred to, described 630-721 



Acrotretida;, classification of 321, 324 



distribution in Cambrian strata 315,316 



genera and species referred to, described 630-721 



62667°— VOL 51, pt 1—12 52 



Acrotretidse — Continued. 



general stratigraphic distribution and number of Cambrian 



genera and species of 112 



number of Cambrian genera and species of 112 



number of genera and species in monograph 113 



number of Ordo\ician genera and species in monograph 113 



Acrotretina;, classification of 321, 324 



genera and species referred to described 665-721 



acuminata, see Lingulella (Lingulepis), 

 acuminata meeki, see Lingulella (Lin^ulepis). 

 acuminata sequens, see Lingulella (Lingulepis). 

 acuminatus, see Obolus (Sckmidtia). 

 acutaTigula, see Lingulella. 



Adairsville, Georgia, locality at 96x 



Adams, Frank D., acknowledgments 12 



Adams County, Wisconsin, localities in 99a, 328k 



Adams Hill, Eureka district, Nevada, localities at 63, 63 



Addison County, Vermont, locality in 227 



Adductor muscles, defined 292 



Adrados, Spain, locality near 350 



advenus, see Obolus. 



affinis, see Obolus (Lingulobolus). 



Agassiz, Alexander, acknowledgments 12 



Age, characters of old age discussed 315 



agnostorum, see Lingulella. 



Agnostus, association mentioned 349, 767 



mentioned 501 



fallal, association mentioned 531 



gibbus, association mentioned 531 



interstrictus, association mentioned 658 



iruyensis, association mentioned 499 



Ixvigatus, association mentioned 476, 700 



Ixvigatus zone (Middle Cambrian), in generalized section for 

 Sweden, Denmark, Finland, and Norway, listing 



species and locahties 145 



localities in 310q, 320b, 320r, 320u, 321p 



parvifrons zone (Middle Cambrian), in generalized section for 

 Sweden, Denmark, Finland, and Norway, listing 



species and localities 146 



locality in 334d 



punctuosus, association mentioned 498 



A graulos sociaiis, association mentioned 498 



agreste, see Eoorthis. 



ismolla, Sweden, locality at 309e 



Cambrian species of, listed 114-119 



generalized section of Cambrian in, Usting included and cor- 

 related species and locahties 147 



localities in 16, 17b, 56c, 56o, 56q, 56u, 89, 90, 90a, 90b, 90c, 



90x, 91, 92x, 93, 93a, 93n, 93o, 93x, 94, 94a, 94o, 94x, 94xx, 

 95a, 137, 138, 139, 139a, 140, 141, 142, 144e, 145, 146, 146f, 361 

 alabamaensis, see Micromitra. 

 dlandensis, see Obolus (Westonia). 



Aland Island, Finland, localities on 311d-f , 311q-t, 311w-y 



alata, see Syntrophia. 



Albany, New York, locality near 72 



Alberta, Cambrian species of, listed 114-119 



localities in 35d, 35e, 35g, 35h, 



57o, 57d, 57g, 57k, 57s, 57y, 58f, 581, 58t, 58w, 68z, 60b 

 species and localities in, correlated with those of British 



Columbia 125-131 



alberta, see Nisusia. 



Albertella helena, mentioned 641 



Albertella Helena fauna, mentioned 457 



Alemtejo, Portugal, locality in 351 



Alexandria Bay, New York, locality near 338j 



Allamakee County, Iowa, locality in 341 



Allan, J. A., Upper Cambrian formations named by 125 



work on Carabro-Ordovician boundary in British Columbia. 125 



AUumette Island, St. La\\Tence River, Canada, locality on 319p 



Alma, "Wisconsin, locality at 328c 



Alpha Station, Nevada, locality near 313c 



alta, see Acrotreta idahoensis. 



Altenhof , Esthonla, Russia, locality at 337e 



Alum slate (Upper Cambrian), locality in 310s 



Alunbruk (alum works), Oeland Island, Sweden, localities at 309], 



309m, 320q, 321x, 390 



Amargosa River, California, localities cast ^i 141, 14n, 14o, 14p 



Amberson, Alabama, locality near. ■ 93a 



