Alan Solem, the curator of invertebrates at the Field Museum of Natural History, created the genus Ba for his newly-described species B.

[2] Solem based his description of the type species B. humbugi on a holotype which the American malacologist Yoshio Kondo had collected in 1938 and three paratypes.

This led to him having an "irresistible impulse" to name the type species Ba humbugi,[4] in reference to the character Ebenezer Scrooge's catchphrase "Bah!

The third paratype was collected in the Sanganaoreva area 5 miles (8.0 km) inland of Ngaloa, Nuku District at an elevation of 950–1,000 ft (290–300 m).

[5] Ba is characterized by having a high spire and an umbilicus which is either completely closed or slightly laterally cracked.

The IUCN estimates an area of occupancy of 12 square kilometres (4.6 sq mi), and its habitat continues to decline due to deforestation.