The Old Covenant law did not directly address lesbianism, though logically it would be just as much of an abomination as homosexuality among males. Paul, however, in Romans Chapter 1 clearly states the evil of lesbianism and attributes the practice to those particularly degenerate cultures.
Actually, I think the old penitentials I cited got it right.
While all homoeroticism involves a sinful misdirection of natural erotic attraction, and St. Paul is certainly on the mark (how should he not be, being one of the Holy Apostles? in seeing the link with social degeneration), only anal sodomy involves an act which is itself so contrary to nature that the corresponding act between a man and a woman is not a common part of normal foreplay. The divinely given Law also seems to take into account the material health of the people of Israel (cf. some dietary prohibitions) and it is a clear fact of epidemiology that the proscribed act is a major disease vector, while the acts lesbians perform are no more likely to transmit disease than normal heterosexual intercourse.
In Orthodox lands, the only sex acts per se ever made illegal (as opposed to being a matter for confession and penance) were those enumerated as abhominations in the Old Covenant law, with the exception of a different extension of the prohibition on anal sodomy: Russian law during the Tsarist period prohibited heterosexual anal sodomy. (In adultery it is the violation of the marriage covenant that adds a degree of sinfulness to the sin of fornication, not the sex act per se.)