Geol.— Vol. I.] SMITH— GLYPHIOCERATID.-E. II3 



Position and Locality. — Glyfhioceras incisum was found 

 in the Fayetteville shale, Warsaw division of the Lower 

 Carboniferous, at Moorefield, Independence County, Ar- 

 kansas, accompanied by Naittilus (Endolohiis) spectabilis 

 Meek, Productus seinireticulatus Martin, P. cora d'Orbigny, 

 Spirifer lineatus Martin, S. gJaber Martin, Terebratula 

 bovidens Meek, and numerous other less characteristic spe- 

 cies. The specimens of G. incisitm from the Moorefield 

 beds agree exactly with those described by Hyatt from the 

 Bend formation, Carbonferous, five miles west of Lampasas, 

 Texas. In the same paper Hyatt^ describes Gly-phioceras 

 cumminsi, also from the Bend formation; he compares G. 

 cimwiinsi io G. striatum Sowerby and G. c?'enistriaVh\\\\^s, 

 finding, however, points of difference from both. European 

 paleontologists now regard G. striatum and G. crenistria as 

 synonymous, and many go so far as to place both as syno- 

 nyms under G. sjphcBricum Martin. To this last species 

 Hvatt compares G. incisum, but finds that G. incisum lacks 

 the crenulations which G. sphcBricum has, and agrees with 

 it in lacking spiral ridges. G. incisum is certainly very 

 nearly related to G. sfhcericum, and if the European forms 

 G. crenistria and G. striatum are all identical with G. 

 sphcerictim, the American form might also very well be 

 classed as a variety under that species, especially as G. 

 incisum as an adult has distinct crenulations. The Europ- 

 ean Carboniferous faunas are turning out to be much more 

 closely related to those of the Mississippi Valley than has 

 been recognized heretofore. In a recent paper the writer^ 

 has described from the Coal Measures of Arkansas the fol- 

 lowing European Coal Measure forms not before known in 

 America: Conocardium aliforme Sowerby, Gastrioceras 

 marianum Verneuil, Pronorites cyclolobus Phillips, besides 

 many others known before in America. Thus the presump- 

 tion is not against the identity of very similar forms in the 

 two regions, but rather in favor of it. 



lOp. cit., p. 467, PI. XLVir, figs. 33-43. 



2Proc. Am. Phil. Soc, Vol. XXXV, 1896, No. 152, "Marine Fossils from the Coal Meas- 

 ures of Arkansas." 



