The neogastropod family Pseudolividae was represented in the Neogene o
f Peru and Chile by a single genus, which we name Testallium to replac
e Gastridium Sowerby, 1846, non Gastridium Sowerby, 1842, or Gastridiu
m Modeer, 1793. Besides the type species, Testallium cepa (Sowerby, 18
46), from the Miocene of Peru and Chile, we recognize T. voluta (Olsso
n, 1932) from the early Miocene of northern Peru, and T. escalonia, sp
. nov. from the Pliocene of Chile. Gastridium retusum Philippi, 1887,
is assigned to Buccinorbis Conrad, 1865.