Metcalf, 1918
Solitary zooids
Test soft, fairly closely adhering to the body wall (Brooksia rostrata). Body elongate, cylindrical, with a strongly developed anterior projection sheathed with 4 longitudinal muscles, which are continuations of the dorsal sphincters, and two ventral longitudinal muscles. Seven body muscles arranged into two groups collected in the mid-dorsal line: MI to MIII and MIV to MVII; MIII and MIV converging or fused laterally. They are interrupted ventrally by two longitudinal muscles which run from MVII to the anterior tip of the anterior projection.
Aggregate zooids
Test very thin and loose (missing in most preserved specimens) (Brooksia rostrata 1, Brooksia rostrata 2). Body oval. Four body muscles continuous both dorsally and ventrally, and arranged asymmetrically. They run either in an anterior-right to posterior-left course or in an anterior-left to posterior-right course, in dextral and sinistral individuals, respectively. Oral intermediate muscle fused with MI to MII and joined with MIII and MIV in the mid-dorsal line. MIV splits into two branches laterally. Ventral and dorsal arrangements similar.
Two species, Brooksia rostrata and Brooksia berneri, are recognized (Van Soest, 1975a) on the basis of differences in the musculature of the solitary zooids (aggregate zooids have not been distinguished yet). Only a single species has been recorded from the South Atlantic Ocean (Esnal, 1968, 1970a):
Brooksia rostrata (Traustedt, 1893)