Visitors from far corners of the Roman Empire might gaze curiously at a small temple in one corner of the atrium. This was the lararium, or household shrine, home to the all-important lares, possibly descendants of farmland gods and penates, spirits of the pantry, who ensured that all household members had enough to eat.
The lares and penates watched over the home, its occupants and the surrounding lands, and small images of the gods were housed in the lararium. Statues and paintings of family lares resemble two young men dancing holding drinking horns aloft.
The husband, or paterfamilias, was the the high priest at his home, and he took the lead in officiating over the daily prayers, assisted by his wife, soon after both arose in the mornings. Offerings of myrtle wreaths, honeycakes and cups of wine were placed before the small images,and the household gods were again remembered at mealtimes, when bits of unfinished food were placed in the lararium. The paterfamilias' birthday was also the feast day of the lar familiaris or genius of the household, the fertility spirit that ensured the continuance of the family line or gens.
Special family events in the family, such as the wedding of a daughter, would be celebrated before the lararium. Special occasions, principally the festivals of the Feralia, Parentalia and Lemuria, were also celebrated at the lararium, where, at times, images of di manes, the divine dead of the family appeared by the well-loved family gods, who were worshipped well into Christian times.
References: The Romans: their Life and Customs, E. Guhl and W. Korner (Senate Press, 1994); Handbook to Life in Ancient Rome, Lesley Adkins and Roy A. Adkins (Oxford University Press, 1998)