652 
Proceedings of Royal Society of Edinburgh. [sess. 
f Interradial spaces with outer ends trilobate ; the 
median lobes homologous to subobsolete intervals 
between the compartments; a central hyaline area 
8. -{ sometimes present ; radii sometimes broad, . . ambigua. 
| Interradial spaces with inner ends acute ; a small 
j round central granule and one at outer end of each 
l interval. Border broad, inner edge angular, . aliena. 
„ f Central area granular or subareolate, . . . 9. 
' \ Central area hyaline, without markings, . . . 10. 
f Inner ends of compartments with short distinct 
I radial lines, 11. 
j No such radial lines. Markings on compartments 
j obscure, at each side of the outer ends of the 
9. intervals a minute granule, ..... kittoniana. 
j No such radial lines. Compartments with inner ends 
j faint, an outwardly concave row of minute puncta 
j stretching between outer extremities of adjacent 
L intervals, ........ traducens. 
f One portion of compartments areolate ; no granules at 
j outer ends of intervals, ..... aemulans. 
11. -j Outer portion of compartments subhyaline or 
I obscurely punctate, a distinct oval granule at one 
l or both sides of outer ends of intervals, . . pulchra. 
[ Markings on compartments obscure, a small round 
j granule opposite the outer end of each interval, . stellulata. 
10. -{ A distinct areola at centro-lateral angle of each 
| compartment, hardly protuberant into interradial 
L space, ......... scutula. 
« j A band of large areolse at inner ends of compartments, 12. 
* | No such areolate band, 13. 
fThe band of large areolae prominent, 2 to 2^ in *01 
mm., the lateral areolae of each compartment not 
protuberant ; inner ends of compartments convex 
inwards ; the intervals expanding gradually out- 
j wards. No central areolate area, .... decor ata. 
12. \ The areolae still longer and narrower (3^ in ‘01 mm. 
across), the lateral areolae protuberant ; inner ends 
of compartments concave towards centre, intervals 
not expanding outwards. A central areolate area, splendida. 
The limiting band of areolae less prominent but 
_ distinct, 14. 
14 . 
( Inner ends of compartments transversely truncate or 
convex towards centre, ...... 
Inner ends of compartments distinctly concave 
towards centre, 
Inner ends of compartments transversely truncate 
or concave towards centre. A single large lanceo- 
late areola bounding each side of the intervals be- 
tween compartments. No central areolate area, . 
Inner ends of compartments concave inwards on each 
side of rays; a delicate irregularly sinuate zone 
contiguous to inner ends of compartments, a minute 
irregular central space, 
15. 
16. 
temrrvma. 
Weissflogii. 
