194 CARBONIFEROUS CEPHALOPODA OF IRELAND. 



of tlie sliell. Inclusion of the wliorls nearly complete ; umbilicns small. ^VTiorl 

 semi-elliptical in cross-section, somewhat higher than wide, indented to about one- 

 third of its height by the preceding whorl. Periphery rather broadly rounded, 

 but with some tendency to flattening. Umbilical zone indistinct, merging with a 

 slight degree of convexity in the sides of the shell. Extent of l)ody-chamber 

 unknown. Apertiire unknown. C-hambers of moderate depth, peripheral lolie of 

 the suture-line very deep, wdth subparallel sides (PI. XLII, fig. 10 c). Test appa- 

 rently marked only with lines of growth, but its bad preservation precludes any 

 detailed description of it. 



Dimensions. 



Specimen in the Museum of Science 

 and Art, Dublin (Geological 

 Survey Collection, No. 547). 



Longer diameter of shell (ajiproximately) . . 75 mm. 



,, ,, nml)ilicus (about) . . 12 ,, 



Height of outer whorl (about) . . .45 ,, 



Thickness at umbilical margin (about) . . 35 ,, 



These measurements are only rough approximations, as the shell is much 

 distorted. 



Affinities. — In the form of the suture-line this species closely resembles Ghjpliio- 

 ceras parnlleliivi, J. Hall, sp.,' especially in the length of the peripheral lolie and its 

 nearly parallel sides. Hall's species was selected by Hyatt as the type of Mnenstero- 

 ceras. 



Remarks. — Only one individual a.'^.'iignable to the present species has come under 

 my notice. The thick form of the shell led me at first to regard it as closely allied 

 to G. (B.) ohtitsnm, but the suture-line when developed contradicted this view, and 

 pointed to affinities with the group of species of which G. (M.) jyirnUrJum, J. Hall, 

 sp., is the typical form. 



Locality. — Balliuacarriga, county of Limerick. 



Gi.YPiiiocEUAS (MrENSTEROPEKAs) Ei.T.irsoiDAi.E, G. G. Crick. Plate XLIII, figs. 1 a — r. 



1899. Gltphioceras ellipsoidale, G. C. Crick. Ann. Mag. Nat. Hist., ser. 7, 



vol. iii, p. 499, fig. 14 



Description. — Shell subglobose, somewhat compressed at the sides, with rather 

 broadly rounded })eri])hei"y ; uml)ilicate(l ; greatest thickness at the umbilical margin, 

 about four-sevenths of the diameter of the shell; height of outer whorl nearly three- 

 ' Thirteenth Eep. New York State Cabinet Nat. Hist., 1860, p. 101, figs. 13, 14. 



