312 BRAXSOX AND GREGER AMSDEX FORMATIOX OF WYOMIXG 



Faux^as axd Correlatioxs 



Three men spent abont five hours in collecting in the locality where 

 the section was made, and specimens of the following species were ob- 

 tained: Zaphrenfis amsdencnsis, Spirifer pellcensis, Spirifer shoslionen- 

 sis, Composiia trinuclea, Eiunetria marcyi, Pugnoides oitumica, Spiri- 

 ferina Ijrowni, Orthotetes kasJiOskensis. Chonetes cliesterensis, Teira- 

 camera subciineata, PhiUipsia sp. ? 



In the Little Popo Agie region, where all of the fossils were collected 

 on the weathered slopes, the fauna consists of the following species : 



ZaphrentiH amsdencnsis 

 Ortoiiia cf. hiatchlcyi 

 OrMcu 1o idea wyomingens is 

 Composita trinuclea 

 DiapJiragmus phillipsi 

 Spirifer ivelleri 

 Spirifer pellcensis 

 Pustula genevievensis 

 Spiriferina hroinii 

 Martinia sp.? 

 Eumetria verneuiUana 

 Pugnoides ottumiva 



Orthotetes Idskaskiensis 

 Sch izophoria sicallori 

 Cliothiiridina h irsuta 

 Meekella amsdencnsis 

 Bulimorpha canal iculata 

 Lo.ionema worth eni 

 Bucanopsis or Bellerophon 

 Myalina sancti-lndovici 

 Microdon cf. ohlongus 

 Criuoid 

 Orthoceras 



The most abundant forms in the Wind Eiver Amsden are Coiaposita 

 trinuclea, Spirifer pellcensis, DiapJii-agmus [jliillipsi, Spirifer welleri, 

 Zaphrentis amsdenensis, and Spiriferina hrowni. 



Composita trinuclea, Eumetria verneuiUana, Spirifer pellcensis, Pug- 

 noides ottiunira, and Orthotetes J^'a^'^Ji-asHensis are positively identified on 

 the basis of minute characters. All of these sj^ecies occur in the Sainte 

 Genevieve of the Mississipj^i Valley and none of them ranges below the 

 Salem. The Salem species, Tetracamera subciuieata and Bulimorplia 

 bulimiformis, are not identified with equal positiveness, but the evidence 

 of most of the species indicates that the Amsden should l)e correlated 

 with the Sainte Genevieve. 



On the other hand, if the Amsden is of the same age as the Sainte 

 Genevieve, Meel-ella, represented by J/, amsdenensis, occurs earlier here 

 than any place else in America. But M. amsdenensis is a non-plicate 

 form, and in this respect is similar to Meel'ella leei, from the Lower Car- 

 boniferous^ of England, and differs from the Pennsylvanian Meekellas. 



Pustula genevievensis has often been identified as Produrfus nehraslc- 

 ensis, but agrees better with the Sainte Genevie\'e form. 



"Memoirs of the Geological Sur\ 

 112-114, pi. 1.3, tigs. 1-2. 



'v of Great Britain. Paleoutology. vol. 1. part 2. 



pp. 



