Subfamily Turbonillinae Bronn, 1849 .

Pyramidellids with elongated, turreted shells, a single columellar ‘tooth’ and large exposed protoconch with its axis at more or less 90° axis of the theleoconch.

Key to the genera of Turbonillinae, based on shell morphology

1a. Shell smooth, or with very fine spiral sculpture in addition to growth lines ...................................................2

1b. Shell with axial sculpture ................................................3

2a. Shell long with numerous whorls ...................... Eulimella

2b. Shell small and smooth with shouldered whorls, planorboid protoconch, usually missing ......... Bacteridium (Incertae sedis)

3a. Shell with only axial sculpture ......................... Turbonilla

3b. Shell with both axial and spiral sculpture ........ Pyrgiscus