  There is a commutative algebra of differential-difference operators, acting
on polynomials on R_2, associated with the reflection group B2. This paper
presents an integral transform which intertwines this algebra, allowing one
free parameter, with the algebra of partial derivatives. The method of proof
depends on properties of a certain class of balanced terminating hypergeometric
series of 4F3-type. These properties are in the form of recurrence and
contiguity relations and are proved herein.
