Color overall is a gray-white, with colonies developing into partially erect branches, clusters and masses of zooids. Zooids are arranged irregularly in clumps along stolons. Individual zooids are subcylindrical in shape, becoming more elongate when the polypide is expanded. Functional zooids average 1.14 X 0.30 mm. Degenerated zooids measure an average 0.575 X 0.25 mm.
Orifice is round with expansion of the polypide, but square in shape when it is retracted.
Polypides have large gizzards that measure approximately 0.119 X 0.139 mm in size. The lophophore is also large, measuring approximately 0.751 mm in diameter, and bears 8 tentacles that are strongly outcurved at the tips. Stolons measure 0.134 mm in width. However, zooids of B. maxima are significantly larger than those of B. gracilis . It has since been documented in Jamaica at both Discovery Bay and Port Royal.