On an overcast day on a cliff above the pounding surf in the sleepy seaside town of Ocean Beach, Calif., just northwest of San Diego, FX’s comedy-drama “Terriers” has pitched camp for the day.

It’s an opportunity for stars Michael Raymond-James and Laura Allen to have a heartfelt, emotional scene, complicated by the restlessness of co-star Buster the bulldog.

But for the close-ups, a sandbag with a leash attached sits in for Buster, and things move more quickly.

At this point, you could be forgiven for some confusion, because the show, premiering tonight, is called “Terriers,” and there’s a dog in it, but it’s a bulldog.

You might think, “Well, that’ll be all explained in the pilot.”

It’s not, but anyone familiar with the scrappy, feisty, dogged persistence of scruffy terriers would recognize those same qualities in the lead characters of the show, two hardscrabble, unlicensed private investigators.

And if you didn’t know about what dog fanciers call “true terrier character,” now you do.

It would spoil a plot point to explain how Buster the bulldog fits into all this, but what can be said is that Donal Logue plays Hank Dolworth, a former police officer who has lost his job, his wife and his good name.

He decides to take up the private-eye business, and his first hire is his best friend, Britt Pollack (Raymond-James), a former home burglary specialist who met his girlfriend (Allen) when he saw her picture after breaking into her home.