TENNESSEIC PEKIOD 555 



Axinura canadensis (it is the genotype of Castelnau's new genus Axinura 

 and is the only species referred to it), and the L. canadensis of authors 

 must become Axinura mamillaris Castelnau (not Fischer). Should the 

 two forms eventually be regarded as one species, the name would then 

 become Axinura canadensis. 



Other Saint Louis guide fossils are Melonites, Archceocidaris wortheni, 

 Pentremites conoideus, P. cavus, Dichocrinus simplex, Cystodictya major, 

 Spirifer Tceokuk littoni, and Eumetria verneuiliana. 



The Saint Genevieve is marked by Michelinia subramosa, Cystelasma 

 rugosum, Lithostrotion harmodites, Amplexus geniculatus, Pentremites 

 florealis, Platycrinus huntsvillce, and Pugnax ottumwa. Ulrich gives 

 many other species (1905, 4?, 48), but all have a longer range than the 

 Saint Genevieve. According to Weller, the latter was the time of greatest 

 transgression. 



The Kaskaskia is the chief fossil horizon of the Chesterian. It is 

 marked by Pentremites godoni and P. pyriformis (also occurs below), 

 P. obesus, P. forbesi, and P. pyramidatus (above), Agassizocrinus, Ptero- 

 tocrinus (above), many Archimedes, Lyropora, Meehopora, Prismopora 

 serrulata, Spirifer increbescens, Spiriferina spinosa, Cleiothyridina royssi, 

 Composita subquadrata, and Eumetria vera. 



As ammonites generally serve as good guide fossils to horizons, it is 

 deemed advisable to give the species found in the Batesville: Goniatites 

 sphcericus and G. striatus (both are European forms). In the following 

 shales, the Fayetteville, occur Bactrites carbonarius, Glyphioceras calyx, 

 Goniatites crenistria, G. newsomi, G. subcircularis, and Gastrioceras en- 

 togonum. 111 



Arctic region. — In the Arctic archipelago Lithostrotion has been iden- 

 tified in at least three localities. The associated species, however, do not 

 make it clear whether the horizon is Tennesseic or Pennsylvanic. Coal 

 beds, possibly of early Tennesseic age, occur in many places in the Arctic 

 archipelago and more certainly at cape Lisburne, Arctic Alaska. It is 

 more probable that these faunas are of Pottsvillian age. 



P ennsylvanic-P ermic Period 

 See plates 83-85, and pages 496-498 



In North America the Permic was not introduced with a new submer- 

 gence, as was the case in Europe and India ; on the contrary, the Pennsyl- 

 vanic transgression attained its maximum spread late in this period, after 

 which there was continuous emergence until the close of the Permic. In 



171 Smith : Monograph 42, U. S. Geological Survey, 1903. 



