To be female is, I think, neither better nor worse than to be male; but it is to be different, it is beyond doubt different. . ."" says editor Silverberg. But anyone would be hard put to define that quality of female differentness on the basis of these three novellas by ""newer"" West Coast writers. All three women have created bizarre, extraterrestrial settings: Vonda Mclntyre's ""Screwtop"" is a prison labor camp on the gruesome planet of Redsun where genetic fascism is law; Joan Vinge's ""Crystal Ship"" takes us to a decaying outpost where the remnant of earthly colonists have been subverted by the natives with a hallucinatory drug; and Marta Randall's ""Megan's World""--the only story of the trio where either feminist feeling or humor is evident--shows how a giant, lavender-hued bionic woman comes to be accepted as a god by a populace of sword and sorcery felines. All three novellas also strike us as topheavy--a lot of elaborate imaginative machinery used to relatively little effect, but that's a problem male writers have with the novella form as well. An extra for aficionados who want to catch up on some newcomers they may have missed (Mclntyre won a Nebula in 1973) or for those who are looking for female sci-fi protagonists.