Ascobulla is a genus of sea snails, a marine gastropod shelled-sacoglossan mollusk in the family Volvatellidae.

A more common term for the organism is “bubble snails.” The description of “bubble-shells'' comes from the shape of the head-shield and large external shell.

Much confusion has occurred in the exact classifications between these species, and living animals of Cylindrobulla and Ascobulla have often been considered to be essentially identical,[2] but more recent research is geared towards distinguishing between the two.

[3] To date, the genus Ascobulla contains 5 species: A. californica, A. fischeri, A. fragilis, A. japonica, and A.

The gill of all shelled Sacoglossa is composed of a series of many parallel, ciliated lamellae, which are folds of the outer tissue layers of the mantle roof and cover the surface of the kidney.

[13] Members of the Ascobulla all have increasing tooth size in their newest teeth, which is another characteristic that distinguishes them from Cylindrobulla.

Ascobulla features a penial stylet, which is able to be turned inside out and is located laterally on the right side.