It is known that using the Cayley-Dickson construction a quaternion $q$ can be written in a symplectic form as $q=x+\mathbf{i}y$ with $x,y \in \mathbb{C}$.

I read in a couple of references that $x$ is called the <i>simplex</i>-part whereas $y$ is called the <i>perplex</i>-part of the quaternion.  Is this widely accepted and if not what is the proper onomatology?

On the same topic is there a standard name for the two Quaternion parts comprising an Octonion?