62 CARBONIFEROUS AMMONOIDS OF AMERICA. 



Genus Glyphioceras Hyatt (emend. Havig). 



In establishing' Ids genus Glyphioceras Hyatt took for the type 

 Goniatiies splicericiis Martin, ah-eady chosen by de Haan as tlie type ot" 

 Goniatites, so that the group of G. sphcericus and G. striatus can not prop- 

 erly come under this genus. But Hyatt divided his genus into two divi- 

 sions, the second of which is characterized by open umbilici, less involution, 

 broader and lower whorls, semilunular or trapezoidal cross section, fine 

 lateral or umbilical ribs. Of the species mentioned by Hyatt under this 

 section Goniatites diadema Goldfuss is the best known. E. Hang" has 

 accordingly proposed to i-etain Hyatt's name for this section, and has selected 

 G. diadema as the type, although the first species mentioned by Hyatt is 

 G. ohtusus Phillips, which belongs to the group of G. striatus. 



This division seems quite satisfactory from the stratigraphic stand- 

 point, for Goniatites s. str. is almost confined to the Vise horizon of the 

 Lower Carboniferous, while Ghjphioceras as thus restricted is more common 

 in the Lower Coal Measures. 



Glyphioceras calyx Phillips. 

 PI. XVIII. 



1836. Gfoniatites calyx, J. Phillips, Geol. Yorkshire. Pt. II, p. 'im. PI. XX, ligs. 



22, 23. 

 1836. Gdiiiatites mutabil^ (pars), J. Phillips, Geol. Yorkshire, Pt. II, j). 236, PI. 



XX; tigs. 24, 25 (not 26). 

 1852. Ainiiion/'ten ve-^ica (pars), C. G. Giebel, Fauna der Vorvvelt, Vol. Ill, p. -ITO. 

 1880. Gmiiatites calyx, L. G. de Koninck, Faune calc. carbon, de la Belgique, Vol. I, 



p. 265, PI. L, fig. 18. 

 1884. Hoiiioceras calyx, A. Hyatt, Proc. Boston Soc. ]^at. Hist., Vol. XXII, p. 330. 



1888. Goniatites calyx, R. Etheridge, British Fossils, Vol. I, Palaeozoic, p. 311. 



1889. Glyphioceras mutalnl,' (pars), E. Holzapfel, Pal. Abhandl., Vol. V, p. 30. 



1897. Glyphiocer'an calyx, Foord and Crick, Catal. Foss. Ceph. Brit. Mus.. Pt. Ill, 



' p. 206. 



1898. Glyphioceras calyx, E. Hiiug, Etudes sur les Goniatites, p. 101. 



This species was selected by Hyatt as the type of a new genus 

 Homoccras, but its characters are common to the young of all members of 

 Glyphioceras when they have just made the transition from the I'rionoceras 

 stage of growth. Holzapfel thought this was the young of G. mutabile Phillips, 

 as, indeed, it may be, but the connection has not yet been demonstrated. 



The shell is much smaller than is usual with the Glyphioceratidse, not 



« ]£tudes sur lea Goniatites, p. 26. 



