Known distribution of Oligodon arenarius (light blue) and O. macrurus (blue) in Vietnam. Stars denotes type locality. Localities: 1 Ho Chi Minh City; 2 Binh Chau–Phuoc Buu Nature Reserve, Ba Ria–Vung Tau Prov. (type locality of O. arenarius); 3 near Phan Thiet city, Binh Thuan Province; 4 Mui Ne, Binh Thuan Province; 5 Mui La Gan, Binh Thuan Province (type locality of O. macrurus); 6 Nui Chua National Park, Ninh Thuan Province; 7 Nha Trang, Khanh Hoa Province; 8 Hon Tre Island, Khanh Hoa Province.