i.e. "the good ones" [mana], is the general name by which the Romans designated the souls of the departed but as it is a natural tendency to consider the souls of departed friends as blessed spirits, the name of Lares is frequently used as synonymous with Manes, and hence also they are called dii Manes, and were worshipped with divine honours.
At certain seasons, which were looked upon as sacred days (feriae denicales) sacrifices were offered to the spirits of the departed with the observance of various ceremonies.
But an annual festival, which belonged to all the Manes in
general, was celebrated on the 19th of February, under the name
of Feralia or Parentalia, because it was more especially the duty
of children and heirs to offer sacrifices to the shade's of their
parents and benefactors.