neii) or Utth-hnown Goniafites/rom Iretand. 43 1 



middle of tlie lateral area and a deep and wide hyponomic 

 sinus on the periphery, wlicre some of them are tliicker than 

 the rest and somewhat regularly placed. Up to a diameter 



Fig. 1, 









Pericydus Foordi.—a, lateral view ; b, peripheral view of the same. Car- 

 boniferous Limestone : St. Doulagh's, Co. Dublin, Ireland. Drawn 

 from an example in the collection of Dr. A. H. Foord, F.G.S. About 

 three fifths natural size. 



of about 56'0 millim. the test is ornamented with rather 

 coarse regularly placed ribs, which are separated by inter- 

 spaces a little wider than themselves and have the same 

 direction as the ornaments of the adult. 



Dimensions. 



(iO (ii.) 



Diameter of shell 106-O mm. (1000) 49-0 mm. (100-0) 



"Width of umbilicus (at suture 



of shell) 32 „ (300) ? 



Width of umbilicus (at its 



margin) 42 „ (394) 250 mm. (ol-Q) 



Height of outer whorl 47 „ (44-1) 



Ditto above preceding whorl . . 28 „ (26'2) 



Thickness of shell 46 „ (43-1) 33-0 „ (67-3) 



As the larger specimen is broken transversely across I 



32* 



