Nassarius insculptuswas first decribed by Philip Pearsall Carpenter in 1864. N. insculptusis more commonly known as thesmooth western nassa mud snail and is found in marine mud, sand, and gravel in California and Mexico. Specimens of N. insculptushave been recovered from Point Arena, California to Cedros Island, Mexico, with lengths varying from 18-23 mm (Demond 1952). Though little research has been done on the depth ranges of these small gastropods, their Pliocene microfossils have been found at depths of 50 to 530 meters (Powell, et. al. 2008).