- Depressions
- Deserts, of Mars
- Deucalionis Regio, neck between it and Fastigium Aryn
- Development, seasonal
- Diameter, of Mars
- Distance
- Double canals
- on map
- account of (and pages following this)
- appearance of
- width between
- manner of doubling
- manner of doubling
- Douglass, A. E.
- Duplication, of canals (See Gemination.)
- Earth
- Eccentricity
- Elysium