Samuel W. Bogley, the two-term Prince George's County Councilman from Bowie, was chosen by Maryland Democratic gubernatorial candidate Harry R. Hughes yesterday to be his running mate in the lieutenant governor's slot on the ticket.

Hughes, the former state secretary of transportation who is a longshot candidate in the Sept. 12 Democratic primary, has spent the past two weeks debating whether to stay in the race. Over the weekend he decided to continue his campain and he selected Bogley for a running mate - as required by law - in time to meet today's deadline for filing his certificate of candidacy.

The completion of the Hughes-Bogley ticket brings to five the number of Democratic gubernatorial slates. The other tickets are: Attorney General Francis (Bill) Burch running with former state Secretary of Economic and Community Development Joseph G. Anastasi; Acting Gov. Blair Lee III running with State Senate President Steny H. Hoyer; Baltimore City Council President Walter S. Orlinsky running with Frederick Mayor Ronald N. Young, and Baltimore County Executive Theodore G. Venetoulis running with Anne Arundel County Council-woman Ann C. Stockett.

Bogley recently told the Prince George's County Democratic Party selection committee that he would not run for relection to a third term, on the county council. He said then that he was returning to the fulltime practice of law and bowing out of politics.

But the opportunity of running for lieutenant governor was too attractive for Bogley to turn down, sources said. He agreed to help Hughes raise the money and gain the organizational support his campaign has been lacking.

It will not be easy since Prince George's already has a favorite son in the race. Hoyer has brought all the county's organizational support to the Lee ticket.

In Prince George's Bogley has been something of a maverick. During his two terms on the county council, Bogley often voted against the wishes of his Bowie constituents and often went against the council majority loyal to County Executive Winfield M. Kelly Jr.

Recently, Bogley initiated a successful fight against the political fund-raising techniques of council president Francis White. Bogley's effort led to a county law against testimonial fund-raising dinners, and finally to White's exclusion from the county Democratic slate for this year's election.

Bogley's image in Prince George's is similar to the reputation Hughes has built in Maryland. Both are seen by their political colleagues as "nice guys" who do not enjoy the political side of government."Sam's a prince of a person, he'd take dead cats off a road, but he has a tough time campaigning," said one Prince George's politician.