Permo -Carboniferous Ammonoids of the Glass Mountains 127 



Number of specimens examined: 



Two. The species seems to be rare, but as it externally resembles 

 somewhat the small individual of Waagenoceras Dieneri n. sp., it may 

 easily be confounded with them where the suture cannot be made out. 



Locality: 



Near junction of Road and Gilliam Canyon, Glass Mountain. 



1 



Stacheoceras Gemmellaro 



Gemmellaro^ in 1888 created the new genus Stacheoceras for dis- 

 coidal forms with more or less rounded flanks, and numerous saddles 

 and lobes; the saddles being entire, high and rounded, the lobes bifid 

 or trifid. As Mojsisovics^ did not think it possible to separate Stach- 

 eoceras from Popanoceras Hyatt, Gemmellaro^ in an appendix to his 

 work, proceeded to defend his opinion, showing the differences be- 

 tween the two genera, demonstrating that such not only exist in the 

 external sutures, but also in the internal ones. In 1889, Karpinsky* 

 accepted the opinion of Mojsisovics and included all the foriTis from 

 the cephalopod-bearing Artinsk in the genus Popanoceras Hyatt. 

 Later on Haug,^ in 1894, recognized the genus Stacheoceras, placing 

 it in the family of Joannitidae, while he considers Popanoceras as be- 

 longing to the Arcestidae. In 1897, Diener^ accepts Stacheoceras as 

 a subgenus of Popanoceras. In 1903, James Perrin Smith'' clearly 

 accepts Stacheoceras as a genus distinct from Popanoceras, but in- 

 cludes his forms with entire saddles and bifid and trifid lobes {P. Ganti, 

 P. Parkeri, and P. Walcotti) in the genus Popanoceras; later on, in 

 1913, he^ considered at least one of these species as belonging .to 

 Stacheoceras (St. Ganti). 



In 1907, Tchernow^ also recognized the validity of the genus Stach- 

 eoceras. He considers Popanoceras Sobolevskyi Vern. as the repre- 



'Gemmellaro, Calc. c. Fusulina, p. 24. 

 ^Mojsisovics, Arktische Trias-Amm., p. 18. 

 'Gemmellaro, loc. cit., app., p. 11. 

 •Karpinslcy, Ammoneen d. Artinsk-Stufe, p. 67, 84. 

 "Haug, Les Amm. du Perm, et du Trias., p. 394. 

 °Diener, Permocarb. fauna of Chitichun No. I, p. 9. 

 'J. P. Smith, Garb. Amm. of America, p. 25, 128, 135. 



'J. P. Smith, in Zittel-Eastman, Text-book of Paleontology, Vol. I, 2nd ed. p. 641, 

 fig. 12-13. 



•Tchernow, L'.gtage d'Artinsk, I., p. 287, 303, etc. 



