Each of the larger islands between Luzon and Mindanao, except Samar and Bohol, is traversed longitudinally by a single mountain range with occasional spurs.
Galeopithecus and Tarsius range from Basilan to Samar; the former occurs also in Bohol.
In Samar there are irregular masses of hills.
On the Pacific coast of Luzon, Samar, Leyte and Mindanao the rainy season is from November to May, when the winds blow from the east or the north-east.
Red or brown deer occur in Basilan, Mindanao, Leyte, Samar and the Calamianes Islands.
Squirrels are confined to the eastern chain of islands from Basilan to Samar and to the Palawan-Calamianes group. In the southern islands there is a tiny species, the size of a mouse.
The first island on which he landed was Malhou, between Samar and Dinagat.
The greatest differences occur between Luzon and Samar and Leyte.
The zoological position of Bohol has not been satisfactorily determined, but all existing evidence indicates that it must be grouped with Samar and Leyte.
These genera usually have distinct representative species in Luzon, Samar and Leyte, Mindanao, and in some cases in Basilan also.
Two thousand persons lost their lives in Samar and Leyte during the great storm of 1897.