A honeycomb body is disclosed having cells extending along a common direction, a first plurality of the cells being open at both ends of the body and a second plurality of the cells being closed at one or both ends of the body, the second plurality of cells arranged in one or more groups of cells cooperating to define one or more fluid passages extending through the body at least in part perpendicularly to the common direction, wherein, in a plane perpendicular to the common direction, the ratio of the area of cells of the first plurality to the area of cells of the second plurality varies along the length of at least one of the one or more fluid passages.