Scatterplots of factor scores from principal components analysis (PCA) of log
-transformed measurements. 4a–c: Ordination of specimens of the eastern Blepsimolge (circles) and Typhlomolge (squares; includes E. rathbuni and E. waterlooensis) clades are shown. Closed and open symbols represent specimens collected from cave and surface localities, respectively. 4d: Ordination of morphological variation within and among cave populations of central Texas Eurycea (PC1 vs. PC2). Populations with N > 3 are shown with colored convex hull polygons (individual specimens removed except for outliers). Light gray circles indicate surface specimens; dark gray circles indicate cave specimens from localities with N ≤ 3.