CAMBRIAN GEOLOGY AND PALEONTOLOGY
II
No. 2.—MIDDLE CAMBRIAN MEROSTOMATA
By CHARLES D. WALCOTT
(With Six Plates)
CONTENTS
| PAGE | |||
| Introduction | 18 | ||
| Cambrian Merostomata | 19 | ||
| Classification | 19 | ||
| Relations to pre-Cambrian Merostomes | 21 | ||
| Sub-order Limulava, new sub-order | 21 | ||
| Family Sidneyidae, new family | 22 | ||
| Genus Sidneyia, new genus | 22 | ||
| Sidneyia inexpectans, new species | 24 | ||
| Cephalo-thorax | 24 | ||
| Abdomen | 24 | ||
| Ventral appendages | 25 | ||
| Cephalo-thorax | 25 | ||
| Abdominal | 26 | ||
| Genus Amiella, new genus | 27 | ||
| Amiella ornata, new species | 27 | ||
| Cephalo-thorax | 27 | ||
| Abdomen | 28 | ||
| Surface | 28 | ||
ILLUSTRATIONS
| Plate | PAGE | |
| 2. | Sidneyia inexpectans | 30 |
| 3. | Sidneyia inexpectans | 32 |
| 4. | Sidneyia inexpectans | 34 |
| 5. | Sidneyia inexpectans and Amiella ornata | 36 |
| 6. | Neolenus serratus and Sidneyia inexpectans | 38 |
| 7. | Sidneyia inexpectans and Beltina danai | 40 |
Smithsonian Miscellaneous Collections, Vol. 57, No. 2
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