Twins George and Tom join Sam in the squad, the first time that three brothers have been selected in an England squad, alongside fellow NRL representatives James Graham (Canterbury) and Gareth Widdop (Melbourne).
Leeds skipper Kevin Sinfield will captain the side, and he is joined by five other Rhinos, who along with Wigan have the largest representation in the squad with six.
Huddersfield forward Brett Ferres will fly with the squad to South Africa this week on stand-by, while coach McNamara also revealed that all members of his ETS squad are on stand-by in case there are any injuries or other problems within the squad.
Other teams represented in the squad include Castleford, Hull, St Helens and Widnes.
McNamara said: “After three years of excellent preprations, we are ready for the World Cup.
“We are fully aware that the World Cup will be fiercely contested and that this squad will need to work extremely hard and play to a very high level to win the tournament and we believe we have selected a squad capable of doing that.
“As we have seen in previous tournaments, we will need all members of the squad ready to step up and make vital contributions and we feel that all 24 players have the ability to do that.”
Squad: Carl Ablett (Leeds), Tom Briscoe (Hull), George Burgess, Sam Burgess, Tom Burgess (all South Sydney), Rob Burrow (Leeds), Josh Charnley (Wigan), Rangi Chase (Castleford), Leroy Cudjoe (Huddersfield), Liam Farrell (Wigan), James Graham (Canterbury), Ryan Hall (Leeds), Zak Hardaker (Leeds), Chris Hill (Warrington), Gareth Hock (Widnes), Michael McIlorum, Lee Mossop, Sean O’Loughlin (all Wigan), James Roby (St Helens), Kevin Sinfield (Leeds), Sam Tomkins (Wigan), Kallum Watkins (Leeds), Ben Westwood (Warrington), Gareth Widdop (Melbourne)