20 CARBONIFEROUS AMMONOIDS OF AMERICA. 



Anarcestes Mojsisovics, Agoniatites Meek, Pinacites Mojsisovics, CelcBceras 

 Hyatt; family 2, PrimordialidfE, including Gephyroceras 'Hja.ti, Manticoceras 

 Hyatt; family 3, Magnosellaridfe, including Parodoceras Hyatt, Toriioceras 

 }lyAtt, Ifcerieceras Hyatt, Sporadoceras Hyatt; family 4, Glyphioceratidse, 

 including Brancoceras [Ayanides] Hyatt, Muenst&roceras Hyatt, Gastrioceras 

 Hyatt, Paralegoceras Hyatt, Prionoceras Hyatt, Glyphioccras Hyatt [with 

 Goniatites de Haan], Dimeroceras Hyatt, Pericyclus Mojsisovics, Homoceras 

 Hyatt [no longer recognized], Nomismoceras Hyatt [now grouped with the 

 Gephyi-oceratidae], Bimorphoceras Hyatt; family 5, Prolecanitidje, including 

 Sandhergeroceras Hyatt, Behreras Hyatt, Prolecanites Mojsisovics, I'luirci- 

 ceras Hyatt, ScJiisioccras Hyatt [now included with the Glyphioceratidae], 

 Tricenoceras Hyatt, Pronorites Mojsisovics, Popanoceras Hyatt. 



Medlicottia Waagen, Sageceras Mojsisovics, and Lobites Mojsisovics were 

 also included by Hyatt in the Prolecanitidae, although onlj' Medlicottia seems 

 to show any relationship to Prolecanites, and that only reuKitely. 



Hyatt's families do not represent genetic series, but are polyphyletic 

 groups of morphological equivalents — independent parallel developments 

 from kindred stocks. 



Before this publication of Hyatt, genera of Paleozoic ammonoids had 

 already been recognized by Waagen" in the Permian of India and Russia 

 as follows: Xenodisctis Waagen, Medlicottia Waagen (as subgenus of Sage- 

 ceras Mojsisovics), Cyclolohiis Waagen. These were classed with the 

 ammonites on account of their resemblance to Triassic genera. 



Gennnellaro's '' inonograph on the Permian cephalopod fauna of Sicily 

 revealed hitherto unsuspected riches in Paleozoic ammonites of the fami- 

 lies Glyphioceratida^, ArcestidiB, Pinacoceratidae, Noritida?, and Tropitidse. 



A somewhat similar fauna was described by Dr. C. A. White'' from 

 the Permian of Texas, with Paralegoceras, Popanoceras, Waagenoccras, and 

 Medlicottia. 



The classic Permian fauna of the Ural Mountains was redescribed and 

 revised by Karpinsky,'' who showed the gradual transition from the Car- 

 boniferous goniatites into the Permian ammonites in the Glyphioceratidse, 

 Arcestidae, and Prolecanitidiie. 



« Pal. Indica, Ser. XIII, Salt Range Fossils, Vol. I. 



i) Fauna calc. Fusulina. 



"•Bull. U. S. Geol. Survey No. 77. 



f'Die Ammoneen der Artinsak-Stufe. 



