new or little-known Goniatites/rom Ireland. 431 



middle of the lateral area and a deep and wide hyponomic 

 sinus on the periphery, where some of them are thicker than 

 the rest and somewhat regularly placed. Up to a diameter 



Fig. i. 



i 



•# 



Pericyclus Foorcli.—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. 



(i.) (ii.) 



Diameter of shell 106-5 mm. (100-0) 49-0 mm. (100-0) 



Width of umbilicus (at suture 



of shell) 32 „ (300) ? 



Width of umbilicus (at its 



margin) 42 „ (39-4) 25-0 mm. (51-0) 



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* 



