36 PPP.
report of progress. james hall.
EXPLANATIONS OF PLATES.
PLATE III.
Eurypterus Beecheri.
Page 30.
| Fig. | 1. | Dorsal view of the specimen described, showing the form of the body, the number, size, and orna mentation of the segments, and also a portion of the large swimming appendages. Chemung group. Warren., Pa. |
PLATE IV.
Eurypterus Mansfieldi.
Page 32.
| Fig. | 1. | The head and first abdominal segment, with the palpi and other appendages attached. A portion of the segment and lower part of the carapace is removed showing the median appendage of the thoracic plate. |
| Fig. | 2. | A small individual, enlarged to three diameters. The palpi of the right side and telson are restored from other specimens. The lateral processes of the segments are not preserved. |
| Fig. | 3. | A specimen of the natural size, represented on a block of shale and showing the ferns and other plant remains with which it is associated. |
| Fig. | 4. | The fourth palpus of the right side enlarged to two diameters, showing the form and surface ornamentation. |
| Fig. | 5. | The second or third palpus from the right side, enlarged to two diameters. |
| Fig. | 6. | The last two joints of the large swimming foot, enlarged to two diameters. |
