66
THE HABITAT OF THE EURYPTERYDA
case. The various realms may be secondarily grouped according to occurrence, as marine and terrestrial. In this latter group, two fur- ther subdivisions may be made according to mobility: the courant and the static waters. I propose the term courant for all terrestrial waters which are constantly moving in a given direction, as do the rivers. The following table brings out these points, of which further discussion will not be given in this paper.
CLASSIFICATION OF AQUEOUS BIONOMIC REALMS ACCORDING TO SALINITY[1]
| CLASSIFICATION | SELECTED EXAMPLES | ||||||
| Type of Salinity |
Range in Permille |
Marine | Courant | Static | |||
| Examples | Per- mille |
Examples | Per- mille |
Examples | Per- mille | ||
| I. Fresh | 0.0–0.2 | Amazon River at Obidos | 0.037 | Lake Erie | 0.134 | ||
| Rhine at Cologne | 0.178 | ||||||
| II. Subbrackish | 0.2–1.0 | Vistula near Culm | 0.201 | Laacher See | 0.218 | ||
| Arkansas R. | 0.794 | Humboldt Lake | 0.928 | ||||
| III. Brackish | 1.0–10.0 | Baltic Sea | 7.80 | Salt River | 1.234 | Palic Lake | 2.215 |
| Rio de los Papagayoa | 9.815 | Lake Biljo | 8.800 | ||||
| IV. Superbrackish | 10.0–20.0 | Sea of Azov | 10.60 | Caspian Sea (in 1878) | 12.940 | ||
| Black Sea | 18.30 | ||||||
| V. Subsaline | 20.0–30.0 | Arctic Ocean | 25.50 | Van Lake | 22.601 | ||
| Hudson Bay | 26.00 | ||||||
| VI. Saline | 30.0–40.0 | Behring Sea | 30.30 | Albert Lake | 39.772 | ||
| Atlantic Ocean | 35.37 | ||||||
| Red Sea | 38.80 | ||||||
| VII. Supersaline | 40.0–289 plus | Tinetz Lake | 289.000 | ||||
- ↑ The examples and salinities in this table are taken from the tables compiled from various sources by Professor Grabau, and given in the "Principles of Stratigraphy" (87). The classification is new.
