GLYPHIOCERAS (BEYRICHOCERAS) DIFFICILE. 171 



apart in O. rofpUa. The rotundity of tlic periplicry and tlie smoothness of tho test 

 are tlie same in both species. (I, {B.) romphiudfiiin, do Koninck,' bears also 

 some resemblance to the present species, but it is a more slender shell and 

 the septa are much closer toi>-ether. The smooth test, rounded peripher)-, more 

 inflated sides, and distant septa distinguish the present species from (/. {U.) siihfntn- 

 caticm, though in spite of these differences, which are rather of degree than of kind, 

 the resemblance between the two species cannot fail to be observed. 



Remarks. — The specific name given to this species refers to the localities 

 whence it was obtained, being in the western part of Ireland. 



Localities. — Ballinacarriga, county of Limerick (301 C, 1519 C.) ; Gari-ihies, 

 county of Kerry (661 C, 3786 C, 4169 C). 



Glyphioc'EUAS (BEYKirnor'ERAs) DIFFICILE, sp. uov. Plate XL VI, figs. 1 a — r. 



De.'icriptvni . — Shell (cast) discoid, thick, somewhat compressed, the greatest 

 thickness at the umbilical margin. Owing, however, to a peculiar distortion of the 

 shell whereby the upper half is shifted sideways in relation to the lower half along 

 a line bisecting the shell diagonally, this measurement cannot be given accurately, 

 but it represents rather less than one-half of the diameter of the shell ; height of 

 the outer whorl somewhat less than three-fifths of that diameter. Inclusion of the 

 whorls nearly complete ; iimbilicus small. Whorl subsagittate in cross-section, 

 somewhat higher than wide. Periphery rather narrowly rounded. As the 

 fragment described is entirely septate, nothing is known of the liody-chamber, 

 Chambers rather shallow. Suture-line as in PL XL VI, fig. 1 '". Test unknown, 

 the fragment that remains being too much eroded to show any trace of orna- 

 mentation. 



Dimensiovs. 



Specimen in tlio Museum of 



Scii-nco and Art, Dublin 



(Geolofjical Survey Collectiun). 



Diameter of shell (cast) (about) . . .76 mm. 



„ umbilicus (about) . . . 10 „ 



Height of OTitcr whorl (about) . . . 42 ,, 



Thickness at umbilical margin (about) . . 33 ,, 



Affinities. — Both in its general form and in the conformation of its suture-line 

 the present species bears a very striking resemblance to Gli/phiuceras IIinpn)iii-iivi, 

 Foord and Crick," and perhaps with better material the identity of the two species 



^ Loc. cit., pi. xlvi, figs. 4, 4rt. 



2 ' Cat. Foss. Ceph. Brit. Mus.,' pt. .3, p. 190, figs. 91 a—c. 



26 



