AFeature Geographic area distinguishby amount of reflected light Cydonia
Arcus, arcūs Arc-shaped feature
Catena, catenae craters tractus Catena
Cavus, cavi Arc-shaped feature Peraea Cavus
Chaos, chaoses Aurorae Chaos
Chasma, chasmata A deep, elongated,ression Eos Chasma
Collis, colles Small hills or knobs Tartarus Colles
Corona, coronae Ovoid-shaped feature
Crater, craters A circular depression Victoria crater
Dorsum, dorsa Ridge Eumenides Dorsum
Facula, faculae Bright spot
Farrum, farra Pancake-like structure, or a row of such structures
Flexus, flexūs A very low curvilinear ridge with a scalloped pattern
Fluctus, fluctūs Flow terrain Tantalus Fluctus
Fossa, fossae Long, narrow depression Mangala Fossa
Insula, insulae Island (islands), an isolated land area (or group of such areas)
surrounded by, or nearly surrounded by, a liquid area (sea or lake).
Labes, labēs Landslide
Labyrinthus, labyrinthi Complex of intersecting valleys or ridges. Noctis Labyrinthus
Lacus, lacūs "Lake" or small plain Ismenius Lacus
Large ringed feature Cryptic ringed features
Linea, lineae A dark or bright elongate marking, may be curved or straight
Lingula, lingulae Extension of plateau having rounded lobate or tongue-like boundaries Gemina Longula
Macula, maculae Dark spot, may be irregular
Mare, maria "Sea"; large circular plain Mare Acidalium
Mensa, mensae A flat-topped prominence with cliff-like edges
Mons, montes Mountain Olympus Mons
Palus,paludes "Swamp"; small plain Cerberus Palus
Patera, paterae An irregular crater, or a complex one with scalloped edges
Planitia, planitiae Low plain Utopia Planitia
Planum, plana Plateau or high plain Daedalia Planum
Promontorium, promontoria Cape"; headland promontoria
Regio, regiones A large area marked by reflectivity or color distinctions from adjacent areas, or a broad geographic region Deucalionis Regio
Rima, rimae Fissure
Rupes, rupēs Scarp Utopia Rupes
Scopulus, scopuli Lobate or irregular scarp Oenotria Scopulus
Sinus, sinūs "Bay"; small plain Aonium Sinus
Sulcus, sulci Subparallel furrows and ridges
Terra, terrae Extensive land mass Terra Cimmeria
Tessera, tesserae Tile-like, polygonal terrain
Tholus, tholi Small domical mountain or hill Hecatus Tholus
Unda, undae Dunes Olympia Undae
Vallis, valles Valley Ares Vallis
Vastitas, vastitates Extensive plain Vastitas Borealis
Virga, virgae A streak or stripe of color