CAMBRIAN GEOLOGY AND PALEONTOLOGY
II
No. 3.—MIDDLE CAMBRIAN HOLOTHURIANS AND
MEDUSÆ
By CHARLES D. WALCOTT
(With Six Plates)
CONTENTS
PAGE | ||||
Introduction | 42 | |||
Holothurians | 43 | |||
Class Holothurioidea | 45 | |||
Family Eldoniidæ, new family | 45 | |||
Genus Eldonia, new genus | 45 | |||
Eldonia ludwigi, new species | 46 | |||
Muscles | 46 | |||
Radial canals | 47 | |||
Alimentary canal | 48 | |||
Genital organs | 49 | |||
Family Holothuriidæ | 52 | |||
Genus Laggania, new genus | 52 | |||
Laggania cambria, new species | 52 | |||
Genus Louisella, new genus | 53 | |||
Louisella pedunculata, new species | 53 | |||
Family Synaptidæ | 53 | |||
Genus Mackenzia, new genus | 54 | |||
Mackenzia costalis, new species | 55 | |||
Scyphomedusæ | 55 | |||
Order Rhizostomæ | 55 | |||
Family Undetermined | 55 | |||
Genus Peytoia, new genus | 55 | |||
Peytoia nathorsti, new species | 56 | |||
Burgess shale. New name proposed in footnote | 51 |
PLATES
Plate 8. | Peytoia nathorsti and Eldonia ludwigi | 58 |
9. | Eldonia ludwigi | 60 |
10. | Eldonia ludwigi | 62 |
11. | Eldonia ludwigi | 64 |
12. | Eldonia ludwigi | 66 |
13. | Laggania cambria, Mackenzia costalis, and Louisella pedunculata | 68 |
Smithsonian Miscellaneous Collections, Vol. 57, No. 3
41