structure and relationships of american 

 labyrinthodontidae 



E. B. BRANSON 

 The University of Chicago 



The term "Labyrinthodontidae" is used in this paper with the 

 same signification as Zittel uses it in his Handbuch der PalaeOntologie. 

 A discussion of the genus Eryops is included here because it was 

 studied by the writer for comparison with the Labyrinthodontidae, 

 and some interesting facts were brought out by this study. 



The first remains of Labyrinthodontidae known from America 

 were discovered by Ebenezer Emmons in the Trias of North Carolina, 

 and were mentioned by him in The Geological Report of the Midland 

 Counties of North Carolina in 1856. The same year Leidy described 

 these remains and proposed the generic name Dictyocephalus for 

 them. 1 In 1866 Cope described some skull bones from the Trias of 

 Chester County, Pennsylvania, and referred them to the European 

 genus Mastodonsaurus. 2 Two years later 3 he founded the genus 

 Eupelor on these skull bones and some teeth from the same locality, 

 but the following year referred the teeth to thecodont reptiles. 4 

 In 1868 he described a skull from the Trias of Chatham County, 

 North Carolina, giving to the genus which it represented the name 

 Pariostegus. 5 In the Report of the United States Geographical Survey 

 West of the tooth Meridian for 1875 h e described some fossils from 

 the Trias of northwestern New Mexico, among which were three 

 sculptured plates that he referred to Typothorax, a genus of Para- 

 suchians; but they are without doubt fragments of a labyrinthodont 

 skull. In 1892 the same writer mentions the occurrence of a form 

 allied to Eupelor from the Docum Beds of northwestern Texas. 6 



1 Proceedings of the Academy of Natural Sciences of Philadelphia, Vol. VIII, pp. 

 255, 256. 



2 Ibid., 1866, p. 250. 3 Ibid., 1868, p. 221. 



4 Transactions of the American Philosophical Society, Vol. XIV, p. 25. 

 s Proceedings of the Academy of Natural Sciences of Philadelphia, 1868, p. 211. 

 6 Geological Survey of Texas, Fourth Annual Report, pp. 12, 17. 



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