Carapace short, height 60% of length. Dorsal margin straight. Rostrum large, broad, blunt and down-turned, its tip reaching to below mid-height (B. nodosa Habitus 1). Ventral margin curves smoothly both anteriorly to incisure, and posteriorly to join posterior margin. Postero-dorsal corners of both valves developed into rounded processes at the end of which open the carapace glands. The process on the right valve is the larger. The valves covered with a sculpture of irregular polygons filled with small pits. In ventral view, the rostra clearly seen tapering anteriorly almost from the midpoint. Frontal organ absent. The first antenna with a long dorsal seta, two long and one shorter terminal setae and a ventral cluster of about 200 fine setae mounted on a ventral pad. The caudal furca with seven claw setae.
The shape of this species is distinctive. The numbers of known Bathyconchoecia species is increasing rapidly as the techniques for sampling close to the sea-bed at great depth are developed. At present there are over twenty known species, but it seems likely that this species together with several of the other Müller forms will eventually be separated off.
Originally described from the vicinity of the Azores, it has now been identified from samples collected off N. W. Africa and the Porcupine Seabight region. 1 (R.R.S. Discovery Map).
Holotype deposited in the Zoological Museum of Copenhagen.
37°00'N 25°45'W off Azores; depth 2400-2450m; date 8 July 1969; gear net mounted on the French Bathyscaph Archimede.