ADDENDA. 105 
transversalibus instructis ; latere inferiore anfractibus planatis ; lineis transversalibus et 
longitudinalibus cancellatis ; apertura subquadrata. 
Shell discoidal, the superior and inferior sides concave, the back narrow, rounded, 
encircled upon its upper part by two rows of tubercles, of which there are about nineteen in 
a volution ; the upper surface has the volutions slightly concave, and traversed transversely 
by obscure varices, proceeding from the tubercles; the lower side is but little more con- 
cave than the other; the volutions are flattened. The entire surface of the shell has deli- 
cate transverse and encircling lines, forming a regularly reticulated surface; the aperture 
is subquadrate. 
A beautiful and remarkably discoidal species. 
Geological Position and Locality. The Great Oolite of Hampton Cliffs ; in the collec- 
tion of W. Walton, Esq. 
Puevrotomaria Barnonica, Lyc. ‘Tab. XLV, fig. 10. 
Testa trochiformi, conoidea, spira apice obtuso, anfractibus convexis lineis transversis et 
perpendicularibus, sub-equalibus, cancellatis ; ultimo anfractu superne tuberculato-nodosis ; 
sinu magno, fascia sinus, plana, transversim lineata, in baso anfractuum sita ; ultimo an- 
fractu basi plano, concentrice lineato ; umbilico subnullo, apertura subquadrata. 
Shell trochiform, conoidal ; spire obtuse ; volutions convex, with cancellated transverse 
and perpendicular lines; the last volution with a row upon the upper part of nodose 
tubercles ; the sinus is large, the fascia of the sinus is flattened and transversely lineated ; 
the base is flattened, and concentrically lineated ; the aperture is subquadrate ; there is no 
umbilicus. 
The encircling lines, of which there are three or four above the fascia of the sinus, are 
more prominent than the perpendicular lines. ‘The height is one third less than the basal 
diameter. : 
Geological Position and Locality. The Forest Marble of the Box Tunnel, near Bath ; 
in the collection of W. Walton, Esq. 
Pirvroromaria Burtonensis, Lyc. Tab. XLV, fig. 8. 
Testa trochiformi, conoidea, anfractibus (s5—6), superne inflatis, nodoso-unaulatis, inferne 
subplanis ; superficie lines transversalibus et perpendicularibus, equalibus, dense cancellatis, 
anfractu ultimo basi concentrice et radiatim lineatis, subconvexo, umbilico subnullo ; sinu 
magno, in medio anfractuum situ ; fascia sinus delicate cancellatis. 
Shell trochiform, conoidal; volutions (5—6), very convex in their upper parts, and 
nodosely undulated ; their lower portions rather flattened; the surface, with encircling and 
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