89 
SPIR1FER rotundatus. 
TAB. CCCCLXI .—fig. 1. 
Spec. Char. Transversely obovate, gibbose, 
longitudinally sulcated ; the middle of the 
lesser valve elevated, convex, smooth ; beaks 
approximating; hinge line less than the 
width of the shell. 
In many respects this resembles the Spirifer pinguis, 
tab. 171 , but it is less rounded, and the elevated central 
portion is not divided as in that species by a sulcus ; the 
corresponding cavity in the other valve has several 
obscure lines along it, and no central division, neither is 
the general aspect of the shell so gibbose ; its edges are 
more acute. 
By no means rare in the Black Limestone of Ireland, 
where the shells are much incorporated with the stone, 
and often distorted without appearing cracked. We 
were favoured with the specimen figured by S. Wright, 
Estp of Cork, who obtained it in Limerick. 
