Adam McBurney is the latest name to be added to the touring party, with the Ulster hooker replacing the injured Dave Cherry. McBurney, a former Ireland under-20 international, will join Edinburgh over the summer.
The tour is an opportunity for some of the nation’s most talented youngsters to get experience of international rugby but there are also some left-field call-ups for the matches against England A on June 27, Romania on July 7 and Georgia on July 14.
With Gregor Townsend away on the Lions tour, Mike Blair will take charge of Scotland as interim head coach.
Here are the 18 new faces in the squad:
13. Cole Forbes (full-back)
Cole Forbes came from New Zealand in January for a trial with Glasgow Warriors. He impressed sufficiently to win a "multi-year" contract and five games later has been called up by Scotland. It's been a whirlwind for the former junior All Black who can play across the back three and qualifies for Scotland through his grandfather from Aberdeen. Photo: Craig Williamson/SNS
14. Rufus McLean (wing)
Rufus McLean made the rugby world sit up and take notice with a wonder try for Glasgow Warriors against the Dragons in March when he ran from his own 22 in the Principality Stadium. The score encapsulated his pace and footwork and marked him out as one to watch. Photo: Craig Williamson/SNS
15. Charlie Shiel (scrum-half)
The Edinburgh scrum-half's call-up affords him the opportunity to emulate his father and grandfather who were both Scotland internationals. Dad Graham Shiel was a gifted centre and stand-off while his grandad, the late Dougie Morgan, played at scrum-half with distinction for both the national side and the British & Irish Lions. Shiel junior is a former Scotland Under-20 cap. Photo: Paul Devlin/SNS
16. Ross Thompson (stand-off)
Ross Thompson was named man of the match for his performance in Glasgow Warriors' win over Edinburgh at Scotstoun in January in what was his first start for the club. The Edinburgh-born stand-off has since gone on to establish himself in Danny Wilson's side, playing with composure and aplomb. Photo: Ross MacDonald/SNS