18G CAEBONIFEROFS CEPHALOPODA OF IRELAXD. 



Gi.YrHiocEiJAs (BEYTdniofERAs) r.TT.ixruE, J. W. SaJfrr, sp. Plate XLIX, fip^. 1. 



1864. GoNiATiTEs niLiNouis, /. W. Salter. Mem. Geol. Suit., Geology of the 



Country around Oldham, p. GO, 

 figs. 14 a — c. 



1885. — — R. Etherulye. Mem. Geol. Sui-v., Geology of the 



Country around Ehyl, Aliergele, 

 and Colwj-n, p. 17. 



1888. — — — Brit. Foss., vol. i, PalfBozoic, p. 311. 



1896. — — H. Bolton. Trans. Manchester Micro. Soc. for 



1895, pp. 130, 134. 



1897. Glyphioceeas bilingue, A. H. Foord and G. C. Crick. Cat. Fcss. Ceph. 



British Museum, pt. 3, p. 192, 

 fig. 93 (suture-line). 



1901. — — Wheelton Hind and J. A. Howe. Quart. Joum. 



Geol. Soc., vol. Ivii, p. 356, etc. 



1902. — — Wheelton Hind. Brit. Assoc. Adv. Sei., Glasgow, 



1901, p. 296, "Life-zones in 

 the British Carboniferous 

 Eocks." 



1903. _ _ _ Ibid., Belfast, 1902, p. 218, etc., 



" Life-zones in the British 

 Carboniferous Rocks." 



Description . — The following is tlie description of this species contained in the 

 ' Catalogue of Fossil Cephalojioda, British Mnseum,' pt. 3, 1897, and is here 

 transcrilied because it is based upon much more complete material than I have at 

 my disposal for describing the species : — " Shell compressed, involute ; greatest 

 thickness at the edge of the umbilictis rather more than four-ninths of the 

 diameter of the shell ; lieight of outer whorl nearly one-half of the diameter of 

 the shell. Whorls (? number); inclusion almost complete; imibilicus infundibuli- 

 form, with angular margin and sloping sides, nearly one-fourth of the diameter of 

 the shell in width. Whorl bluntly sagittate in section, a little higher than wide ; 

 indented to aliout two-fifths of its height by the preceding whorl ; periphery 

 convex, a little flattened ; sides feebly convex, with a double spiral furrow neai- the 

 |)('ri[)lu'ry, their ])ortion internal to tlie furrow flattened; inner area distinctly 

 marked off, narrow, slojiing towards the umlnlicus. Body-chamber occui)ying a 

 complete whorl ; aperture with a projecting tongue-like lobe on either side near 

 the periphery, and a deep broad hyponomic sinus. Chambers rather shallow. . . . 

 Test thin, its surface delicately reticulate ; transverse sti-iae very finely crenulate, 

 strongly arched forAvard at the double concentric grooA'e and forming a deep broad 

 sinus on the jieriphery ; longitudinal striae very feeble." 



"All the examples of this species in the Jermyn Street Museum are either very 



