Geol.— Vol. I.J SMITH— GLYPHIOCEKATW^. 107 



It was known to Quenstedt and L. von Buch that ammon- 

 ites went through a goniatite stage in their youth; but these 

 earHer paleontologists did not realize the importance and 

 value of this fact, since they did not connect the idea with 

 evolution, and hence they did not use their knowledge as a 

 guide in classification. But we now know that the only 

 way ever to work out the phylogeny of the ammonites is to 

 study the development of the goniatites. 



Classification of Goniatites. 



Beyrich^ first recognized the unwieldiness of the old 

 genus Goniatites and attempted to subdivide it as follows : 

 I. Naiitilini (Anarcestes and Mimoceras). 2. Siniplices 

 (Tornoceras, Brancoceras, and Prionoceras). 3. Aeqiiales 

 (Sporadoceras and Prolecanites). 4. Irregular es (Belo- 

 ceras). 5. Primordiales ( Gephyroceras). 6. Carbonarii 

 ( Glyphioceratidce p. p. Glyphioceras and Gastrioceras). 

 This classification still holds sway, except in text- books of 

 paleontology; for the genera and families into which later 

 writers have divided the goniatites have not generally been 

 accepted by paleontologists. 



Afterward another classification was attempted by G. and 

 F. Sandberger,^ which agreed substantially with that of 

 Beyrich, except in the names given to the groups. Neither 

 the divisions of Beyrich nor of Sandberger were intended 

 to represent genera or families, for they mostly contain het- 

 erogeneous elements; and even at that time the old genus 

 Ammonites, comprising several times as many species as the 

 goniatites, and very much more various in form, was still 

 considered a unit. 



The first attempt to distinguish genera among the gonia- 

 tites was made by Dr. E. von Mojsisovics^ in 1882, who 

 named Anarcestes, Aphyllites, Pinacites, Pronorites, Prole- 

 canites, and Pericyclus, and brought them into rather fan- 



ifieitr. Kennt. Verstein. Rhein. Uebergangsgebirge. Abhandl. Berlin Akad. Wiss., 

 1837. 



2 Verstein. Rhein. Schichtensystems in Nassau. 



3 Cephalopodeu d. Mediterranen Trias-Provinz. 



