Richard M. Heiberger and Burt Holland Trellis Extensions ************************************* We have designed several multi-panel graphical displays for which the panels are defined by the Cartesian product of one set of variables or parameters with another set. The traditional scatterplot matrix splom is the special case where both the row and column sets of variables are the same and the panels are ordinary scatterplots. Our displays extend the interpretation of the model formula to allow the panels to be functions of parametric transformations of the variables in the formula. We show examples of scatterplot matrices with different sets of variables along the rows and columns, of a ladder of powers display, of interaction plots, of ANCOVA plots, of Least Squares plots, and of Time Series plots.