Page:Pennsylvanian invertebrates of the Mazon Creek Area, Illinois Eurypterida.djvu/18

 . 45. Carapace of Adelophthalmus mazonensis (Meek and Worthen) from the Herdina collection (H-2), showing the outline of the ventral shield; × 2.8. The scales on the ventral shield point outward (see fig. 46).