38 PPP.
report of progress. james hall.
| Fig. | 5. | An enlargement, to ten diameters, to show the change from the acute scales near the margin to short and more rounded forms. |
| Fig. | 6. | An enlargement from the middle of a segment, showing the minute imbricating scales along the anterior portion and large, triangular scales on the middle and lower portion. The figure represents also the posterior and anterior portions of the adjacent segments. |
| Fig. | 7. | An enlargement of the test where it is ornamented with narrow, triangular scales. |
| Fig. | 8. | Enlargement showing small and large rounded imbricating scales. |
| Fig. | 9. | A small carapace showing the characteristic elongate form of this part of the animal. |
| Fig. | 10. | The caudal spine of a small individual. |
| Fig. | 11. | A fragment of shale preserving two detached lateral processes of the segments, enlarged to two diameters. |
Eurypterus stylus.
Page 34.
| Figs. | 12, | 13. Two carapaces referred to this species, showing their form and ornamentation. |
| Figs. | 14, | 15. Two individuals of this species, showing the broad form of the body and the strong telson. |
Undetermined fragments.
| Fig. | 16. | A fragment of shale preserving several fragments of somites of undetermined specific relations. |
| Fig. | 17. | An obscure fragment, possibly a portion of an ectognath. |
Eurypterus pennsylvanicus.
Page 31.
| Fig. | 18. | A view of the carapace described, showing its broad form, produced posterior angles and the arrangement of the nodes on the surface. |
