How has the statute of limitations been interpreted in civil litigation?

He filed individual complaints against appellees under 42 U.S.C. Secs. 1983 and 1985 on August 15, 1983, three to four years after the alleged constitutional violations occurred. The district court consolidated and dismissed the complaints sua sponte on the ground that they were barred by the statute of limitations. We reversed in an unpublished memorandum disposition because the trial judge prematurely dismissed before process was issued and served. Krug v. Imbordino, No. 742 F.2d 1462 (9th Cir.1984) (unpublished memorandum disposition). We explained that the statute of limitations was not jurisdictional, but rather an affirmative defense. Id. Additionally, we explicitly stated that "we make no comment on the merits of the action." Id.