Table 5. Inverse relationships among characters for variation among genera. Summary from Table 4, with characters illustrated in Figure 2.

Principal Component Axis	Among Genera Potential inverse relationships shown across columns for each PCA
PCA-1	All characters large	All characters small

PCA-2	Aperture spacing	Aperture Diameter (AD)
	Along Branch (AAB)	Dissepiment Width (DW)

PCA-3	Node Diameter (ND)	Fenestrule Length (FL)
	Aperture spacing	Node spacing (NS)
	Along Branch (AAB)	Fenestrule Width (FW)

	Aperture Diameter (AD)

PCA-4	Node Diameter (ND)	Branch Width (BW)
	Node spacing (NS)	Dissepiment Width (DW)
	Aperture Diameter (AD)

PCA-5	Aperture Diameter (AD)	Dissepiment Width (DW)
	Aperture spacing Laterally	Aperture spacing
	across Branch (ALB)	Along Branch (AAB)
		Node Diameter (ND)