612 
Proceedings of Eoycd Society of Edinburgh. [sess. 
f Markings to If in ’01 mm., at border a single 
| band of subquadrate areolae 3 in *01 mm. , 
ok ! Markings 2^ to 3 in ‘01 mm., smaller towards 
6S> ' j border, not robust. Border about f of radius, 
broad, with distant evident striae, . 
L Markings otherwise, 
f Markings areolate to about semiradius, on outer 
36. -J portion distinct radial flexuous lines, 
( No such lines, 
f Markings towards centre 3, decreasing rapidly 
j outwards, at border 6, in *01 mm. Border 
o-k j striae coarse, ....... 
'* j Markings 3^ in *01 mm.; apiculi long, delicate, 
j inserted at inner edge of border, and extending 
l beyond circumference, 
31. 
Markings rounded, granular ; towards centre 5, 
towards border 8, in ’01 mm. ; at intervals 
near border delicate, clear, elevated lines, 
Markings largest and irregular beyond semi- 
radius, smaller towards centre and border ; 
rows radial. A rosette, .... 
Appearance otherwise, . 
gg / At centre a large prominent nodule, . 
‘ \ No such nodule, .... 
r Markings in conspicuous, regular, concentric 
circles, . . . . . . 
Markings robust, 2| in *01 mm., punctate, sub- 
regularly, but more obscurely concentric ; 
og ! radial rows obscure, 
* j Markings small, round, granular, subequal ; 
I radial rows inconspicuous, secondary irregu- 
I larly concentric bands evident. A minute 
| central rosette, ...... 
I No such concentric arrangement, 
f Rows inconspicuously radial, on outer portion 
obscurely fasciculate secondary oblique out- 
j wardly curved decussating rows distinct 
' j towards border, ...... 
| Rows radial, ....... 
I Rows oblique and decussating, .... 
' Surface rising for about f of radius, here descend- 
ing abruptly, thence flat to border ; markings 
areolate 3, increasing outwards to 2| in ’01 mm. 
on highest zone, here decreasing suddenly, and 
from this to border subequal. A rosette, 
Surface with central portion convex and sharply 
^ defined. Markings areolate. A rosette, 
' j Surface with central portion funnel-shaped. 
Markings granular, decreasing from edge of 
. central portion to border, .... 
Surface regularly convex between centre and 
border. Markings subequal, areolate, 3| in 
•01 mm. Border striae 5 to 6 in ’01 mm., 
^No such surfaces, ...... 
( Markings somewhat excentric, 4 to 4 \ in 
43. -| ’01 mm. ; rows curved, ..... 
[No such excen tricity or curvature, 
megacoccus. 
irregularis. 
36. 
subareolatus. 
37. 
turgidus. 
nottmghamensis. 
armatus. 
inoequisculptus. 
38. 
nodulifer. 
39. 
patina. 
velatus. 
radiopundatus. 
40. 
decrescens. 
41. 
42. 
epiphanes. 
umbonatus. 
bathyomphalus. 
luduosus. 
43. 
elegantulus. 
44. 
