BRITISH nostalgia for colonial days isn't limited to literary remembrances of the Raj. Despite the current troubles in Northern Ireland, there are still vestigial yearnings in some circles for the ``good old days'' when Ireland was part of the Empire. The dream overflows with visions of country mansions, fox hunts, mutton fillets, and perhaps even that ambiguously glorious position of provincial authority known as Resident Magistrate (R.M.). The Irish R.M. (PBS, Sunday, May 25 9-10 p.m., check local listings) is ``Masterpiece Theatre'' at its most British. This five-part continuation of a series first aired stateside two seasons ago tracks Maj. Sinclair Yeates, who leaves England in 1895 to become an R.M., a kind of British legal umpire sent to an Irish court to bring justice -- and, incidentally, English civilization and manners -- to local benches.
Based on stories written by two Irish cousins, Edith Somerville and Martin Ross, and adapted for television by Rosemary Anne Sisson, ``The Irish R.M.'' is not as melodramatic as ``Jewel in the Crown'' but, in its own way, it is as vivid a depiction of a period when ``the sun never set . . . .''
Peter Bowles plays the retired British Army officer of the title role to perfection. He and his charming wife, played with natural grace by Doran Godwin, are both delighted and confused by the lifestyle and attitudes of their new Irish subjects -- pardon me, neighbors.
Two seasons ago ``Masterpiece Theatre'' presented the first series of ``R.M.'' episodes, and in this series all the main characters return. Peter Sykes and Roy Ward Baker directed the series with a light touch, making certain that the wily Irish always manage to outmaneuver the unwary English.
The premi`ere episode -- ``A Home! A Horse!'' is full of lighthearted nonsense about a job cook, a horse that lies down in the water when confronted by a river, and, of course, the whimsical, devious landlord. Most fascinating is the seemingly accurate picture of the social mores of the period, with constant peeks into luxurious Irish country mansions. Most difficult are the accents, which range from upper-class English to lower-class Irish and which sometimes need translation for American audiences.
``The Irish R.M.'' is an acquired taste, like plum pudding, Irish oatmeal, and kippers. But once you get your teeth into it, you'll want to make it a regular part of your weekly TV menu.