Character. (B.) Cells turbinate, distant. Opening directed more or less upwards. Mouth submarginal. Several curved spines, marginal or submarginal.
1. B. tuba, n. sp.
Opening round, looking nearly directly upwards; a digitiform hollow process below the outer border supporting 2 to 4 long incurved spines; 2 to 3 other long curved submarginal spines behind or above the opening, none below it in front--a solitary spine on the back a short way down the cell. Avicularia very long, trumpet-shaped, arising on the back of the cell.
Habitat: Bass Strait, 45 fathoms.
This species is at once recognisable by the remarkable form and unusual position of the avicularium, and also by the peculiar digitiform spiniferous process on the outer side of the opening.
2. B. gracilis, n. sp.
Cells elongated, slender, opening round or suboval, looking obliquely forwards and upwards; three marginal (sometimes slightly submarginal) spines above and behind the opening, and two much longer curved hair-like spines arising from the anterior and lower edge of the opening. Ovicells globose, subpedunculate, attached to the upper and inner part of the margin of the opening. Avicularia small, like birds' heads.
Habitat: Bass Strait.
A delicate slender species, not unlike B. ciliata or avicularis in habit. The two long spines arising from the anterior edge of the opening suffice to distinguish it from the former of these two species.
3. B. grandis, n. sp.