Question: Don Barry Mason was the founder of the Psychedelic Shamanistic Institute (PSI), which other member that's Welsh, that died on 10 April 2016?

Context articles: Australian twenty five-cent coin
Charles Cardoza Poindexter
2016–17 British and Irish Cup
The Ride Tour
2015–16 A-League
Howard Marks
Marching On Together
Matthew Mason (Welsh cricketer)
Here It Comes Again (The Fortunes song)
Don Barry Mason

The twenty five-cent coin of the Australian decimal currency system was issued as a part of a 14 coin collectors set on from the 10 April 2016 to the 23 April 2016.
 The coins were sold for $3 in conjunction with a local news corp paper.
Charles Cardoza Poindexter (March 10, 1880 – June 3, 1913) was a professor at Fisk University.
 Poindexter was also known for being the precursor, but not a Founder, of the oldest intercollegiate fraternity for blacks in America, Alpha Phi Alpha, who later on became a prominent member and influence in Omega Psi Phi, using his earlier experience to develop much of the framework.
 He is credited with suggesting the "Phi" in the name Omega Psi Phi, as well as the color "Old Gold".
The 2016–17 British and Irish Cup was the eighth season of the annual rugby union competition for second tier, semi-professional clubs from Britain and Ireland.
 London Welsh are the defending champions having won the 2015–16 final against Yorkshire Carnegie 10–33 at Headingley Carnegie Stadium, Leeds on 10 April 2016.
 There have been six different winners and six different losing finalists in the seven seasons of its existence.
 The format of the competition is similar to last season with Scottish clubs not competing.
 For the second consecutive season the four Welsh teams are the reserve sides of the teams competing in the Pro12 competition instead of clubs from the Welsh Premier Division.
The Ride Tour is the ongoing second concert tour by English indie rock band Catfish and the Bottlemen, in support of the group's second studio album "The Ride".
 The tour was announced in February 2016 and began on 4 April 2016, in Glasgow, United Kingdom at the O2 Academy Glasgow.
 The tour is planned to travel across Europe and North America with a total of 50 shows planned so far.
 On 22 February 2016, the band announced an April 2016 stint of shows in UK, including Glasgow, Halifax, Southend On Sea, Doncaster, London and Brighton.
 The band will also headline several festivals across the UK throughout the summer, including Liverpool's 'Sound City' in May 2016, Bristol's Summer Series in July 2016 and Manchester's Castlebowl in July 2016.
 On 14 March 2016 it was announced that the band will play several dates in North America in June 2016.
 The band are also scheduled to play several European festivals this year, including Scotland's T in the Park, Spain's Benicàssim festival, Cumbria's Kendal Calling in July 2016, Cornwall's Boardmasters Festival in August 2016 and Germany's Lollapalooza in September 2016.
 The band will also support Welsh rock band Stereophonics on their Wrexham, Racecourse Ground stadium gig in July 2016, as part of their Keep the Village Alive tour.
The 2015–16 A-League was the 39th season of top-flight soccer in Australia, and the 11th since the establishment of the A-League in 2004.
 Melbourne Victory were both the defending A-League Premiers and Champions.
 The regular season schedule was released on 29 June 2015.
 The season commenced on 8 October 2015 and concluded on 10 April 2016.
 The finals series commenced on 15 April 2016 and concluded with the 2016 Grand Final, held on 1 May 2016.
Dennis Howard Marks (13 August 1945 – 10 April 2016) was a Welsh drug smuggler and author who achieved notoriety as an international cannabis smuggler through high-profile court cases.
 At his peak he claimed to have been smuggling consignments of the drug as large as 30 tons, and was connected with groups as diverse as the CIA, the IRA, MI6, and the Mafia.
 He was eventually convicted by the American Drug Enforcement Administration and handed a 25-year sentence to be served at Terre Haute; he was released in April 1995 after serving seven years.
 Though he had up to 43 different aliases, he became known as "Mr Nice" after he bought a passport from convicted murderer Donald Nice.
 After his release from prison, he published a best-selling autobiography, "Mr Nice", and campaigned publicly for changes in drugs legislation.
"Leeds!
 Leeds!
 Leeds!"
 (commonly known as "Marching On Together") is the name of the anthem of Leeds United A.F.C. Unlike many football songs that are just new words set to existing music, "Leeds!
 Leeds!
 Leeds!"
 is an original composition by Les Reed and Barry Mason.
 The song first appeared in 1972 as the B-side of the record released by Leeds United to coincide with the team reaching the 1972 FA Cup Final, the A-side being titled "Leeds United".
 The vocals on the original recording were sung by the then-members of the Leeds United team and their supporters.
 The record stayed in the UK Singles Chart for almost 3 months, peaking at number 10.
Matthew Barry Mason (born 24 November 1984 in Swansea) is a Welsh cricketer.
 Although he has made a number of appearances at second XI level for Glamorgan, as of the end of the 2006 season his only senior appearances had been three games in the C&G Trophy for Wales Minor Counties, in which he took a total of four wickets.
"Here It Comes Again" is a song written by Barry Mason and Les Reed in 1965.
 It was recorded by The Fortunes and released on 10 September 1965.
 It reached number four on the UK Singles Chart and number twenty-seven on the U.S. "Billboard" Hot 100 chart that same year.
Don 'Barry' Mason (1950–2006) was the founder of the Psychedelic Shamanistic Institute (PSI), a networking organisation that encouraged ethnobotany and scientific research into cannabis and other psychoactive plants while contributing substantially to the public debate about drug policy reform.
 Associates of PSI include: Mathew Atha, Colin Angus, Brian Barritt, Michael Carmichael, Fraser Clark, Paul Devereux, the late John Entwistle, Paul Flynn MP, Ben Ganly, Lee Harris, Mike Jay, Howard Marks, Dr John Marks, Jonathan Ott, Dr Russell Newcombe, Richard Rudgley and Youth.