GONIATITES. 81 



It will be seen from the foregoing description that G. striatus is directly 

 intermediate in character between G. crenistria find G. splmricus, and a large 

 suite of specimens of all three would probably show transitions from one to 

 the other. 



There seem to V)e among the American specimens two rather well- 

 marked varieties of this species, one with the spiral lines very sharp and the 

 cross stripe very weak; this one occurs in the St. Louis-Chester stage of 

 Batesville, Ark. ; the other lias the spiral lines and cross striae of about equal 

 strength, and very sharply defined crenulations ; this occurs in the St. Louis- 

 Chester stage, the Bend formation of central Texas (Glyphioceras cum- 

 minsi Hyatt, PI. X, figs. 1-11), although it seems to the writer that Hyatt 

 has included under this designation specimens of both G. striatus and 

 G. crenistria. Li youth these varieties can not be distinguished from each 

 other, nor from (r. crenistria, which is associated with them. 



Goniatites kentucldensis Miller is probably identical with this species, 

 but until a specimen is found showing constrictions it is left under its 

 present name. 



Occurrence. — Goniatites striatus is characteristic of the upper part of 

 the Lower Carboniferous in Great Britain, Belgium, and German}-, and is 

 considered a typical zone fossil in that region. We may therefore extend 

 the term zone of Goniatites striatus to the same horizon in America, the 

 St. Louis-Chester stage, in which this species has been found near Bates- 

 ville, Ark. (PI. XXVI, figs. 6-13), and in the Bend formation near Lam- 

 pasas, Tex. (PI. X, figs. 1-11). The specimens figured on PI. XXVI, figs. 

 6-13, in this paper are deposited in the geologic collection of Leland 

 Stanford Junior University, and came from the St. Louis-Chester beds 

 (Fayetteville shale) of Batesville, Ark. Those figures on PI. X, figs. 1-11, 

 came from the Bend formation near Lampasas, Tex., and are deposited in 

 the Texas State Museum'. 



Goniatites subcirculaeis Miller. 

 PI. XXVI, figs. 14-18. 



1889. Goniatites suhcirculurix, S. A. Miller, North American Geol. and Pal. p. 440, 

 %. 741. 



This species resembles somewhat G. striatus, but has wider umbilicus, 

 coarser spiral striw, more compressed whorl, and lacks entirely the 



MON XLII — 02 



