confined to the deserts, but extends in a modified form over the areas of more or less vegetation.
There are thus two kinds of spots in the dark regions: those on their borders, and those in their midst. The position of the former—on the edge of the great deserts—implies a difference in kind, further emphasized by their shape. Following is the list of both kinds detected at Flagstaff:—
SPOTS IN THE DARK REGIONS.
Spot at the mouth of the Phison.
"Daix on the Mare Icarium.
Spot at the mouth of the Daix on the Sabaeus Sinus.
Spot on the Socratis Promontorium.
Spot on the western side of the Socratis Promontorium.
Spot at the mouth of the Jamuna on the Aurorae Sinus.
"Ambrosia on the Mare Australe.
"Maeander on the Aonius Sinus.
"Gorgon on the Mare Sirenum.
"Titan on the Sinus Titanum.