630 
Proceedings of Royal Society of Edinburgh. [sess. 
and separated around the border by narrow hyaline lines ; non- 
apiculate. Border hyaline. 
Habitat. — Cambridge deposit, Barbados (Johnson !). 
B. excellens , sp. n. — Diam. *07 mm. Central space obtusely 
triangular, about t l of diameter broad, not sharply defined. Mark 
ings towards the central space subcircular, soon becoming areolate ; 
the circlet of large areolae about f of radius from centre ; within 
this circlet the markings subequal, 4 in -01 mm., in evident curved 
oblique decussating rows ; beyond the circlet decreasing gradually 
outwards from 5 or 5-|- to 8 in *01 mm.; minute apiculi at intervals 
of ’0075 mm., inserted close to the border. Border striae delicate, 
14 in -01 mm.— (PI. III. fig. 16.) 
This species was labelled by Greville B. splendida , but his 
specific name cannot be adopted, since the distinct Heterodidyon 
splendidum now becomes B. splendida. 
Habitat. — Barbados deposit (Greville !). 
B. hyperborea, Grun. Van Henrck, Syn. Diat. Belg ., pi. cxxviii. 
fig. 8. — Diam. *065 mm. Central space and rosette absent. Mark- 
ings areolate; the circlet of large areolae about J of radius from 
centre, within this circlet the markings subequal, 3 to 3^ in '01 mm., 
in substraight decussating rows, beyond the circle subequal, or 
decreasing but slightly near the border, 5 in *01 mm. Border 
hyaline. — Grun., Denk. Wien. Ah, 1884, p. 70, pi. ii. (B), fig. 64. 
Habitat. — Dredged by U.S.S. Gettysburg, lat. 35° 25' N\, long. 
69° 42' E., in 2924 fathoms; marine deposit, Franz Josefs Land 
(Grunow). 
B. elaborata. Grev., Trans. Micr. Soc. Lond., 1861, p. 73, pi. ix. 
fig. 1. — Diam. *08 mm. Central space absent; an inconspicuous 
rosette. Markings areolate ; the circlet of large areolae about f of 
radius from the centre, within this circlet the markings increasing 
slightly outwards from the rosette 3 to 3J in *01 mm., in inconspicu- 
ous radial, and secondary oblique curved decussating rows ; beyond 
the circlet increasing in breadth uniformly, but somewhat rapidly 
outwards, but subequal radially, 4 in *01 mm. Border hyaline. 
Habitat. — Barbados (Johnson !). 
B. coronata. Balfs in Pritch. Inf., p. 940 ; Craspedodiscus 
