Twenty-two from PRO12 champions Glasgow were included while European Challenge Cup finalists Edinburgh provided 12. The squad will be reduced to 31 for the tournament in England in September.
Several players from the English league are in the squad including Premiership winners Jim Hamilton and Duncan Taylor, and Challenge Cup winner Greig Laidlaw.
Six are striving to feature in their third World Cup, John Barclay (back row), Chris Cusiter (scrumhalf), Alasdair Dickinson (prop), Ross Ford (hooker), Jim Hamilton (second row) and Sean Lamont (wing).
Scarlets flanker Barclay features in a national selection for the first time since 2013.
Wasps stand-off Ruaridh Jackson is also in contention having recovered from a season-long knee injury.
"The selection process was made easier by some good performances from a number of players especially in the latter part of the season," Cotter said.
"Hopefully the confidence the players have gained from their successes will filter through into the rest of Scottish rugby. We'll need that for this campaign."
Scotland face France, Ireland and Italy as part of their build-up to the World Cup.
