636 Proceedings of Boy at Society of Edinburgh. [sess. 
A. dabia. Grey., Trans. Micr. Soc. Lond ., 1862, p. 54, pi. vii. 
fig. 41. — Diam. *0375 mm. Central space quadrate, with sides 
slightly concave, hyaline. Markings : rays hardly differentiated, 
interradial spaces 4, cruciform ovate, their inner ends rounded, 
the outer subacute, homologous to the intervals between the com- 
partments; two distinct subparallel radial lines extending from 
their inner ends to the sides of the protuberant outer extremities, 
an evident round clear granule adjacent to the border and opposite 
the outer ends of each interradial space; the compartments extend- 
ing to edges of central space, subhyaline. Border distinct, its inner 
edge round. 
Habitat. — Barbados deposit (Greville !). 
A. aliena. Grev., Trans. Micr. Soc. Lond ., 1862, p. 55, pi. viii. 
fig. 46. — Diam. -0525 mm. Central space circular, about *01 mm. 
broad, not sharply defined. Markings : a minute clear round 
granule at middle of central area ; rays broad ; interradial spaces 
expanding uniformly outwards, the sides straight, their outer ends 
placed obliquely to the direction of the intervals, two faint sub- 
parallel lines extending between their inner ends and the edges of 
the intervals; the compartments reaching almost to the semiradius, 
subhyaline; the intervals narrow, of uniform breadth, a small 
round granule at their outer extremities. Border about f of radius 
broad, subhyaline, its inner edge slightly angular, the angles 
corresponding in position to the outer ends of the intervals. 
Habitat. — Barbados deposit (Greville !). 
§ 4. Traducentes. 
Sometimes regularly polygonal. Central space distinct, granular 
or subareolate, rarely hyaline. Kays narrow. Compartments sub- 
hyaline, or their inner edge with a distinct band of larger areolae, 
their outer portion subareolate or granular. 
A. stellulata. Grev., Trans. Micr. Soc. Loncl., 1862, p. 54, 
pi. vii. fig. 40. — Sometimes regularly and obtusely polygonal. Diam. 
•045 mm. Central space irregularly concavo-convex, about 
*0075 mm. long by *005 mm. broad. Markings: rays 7 to 9, 
straight, regular; the compartments reaching about •§ of radius 
inwards, their inner ends sigmoid on each side of, and protuberant 
