Genus Pterosoma Lesson, 1827
Pterosoma is monospecific. It is a large shelled pelagic snail, up to 4 cm long, with a mainly transparent body. The body can never withdrawn into the shell. The shell is very low, conica-flattened. Only the broad visceral mass is darkly pigmented, the large eyes with black retina and the mouth organs are also clearly seen. The intestine is frequently full and visible. The body is elongate, flattened with one swimming fin and small tail (Pterosoma planum).
[1 species]