Collection place
- Machiqurg, Venezuela2 objects
- Mad River slough, Humboldt County, California19 objects
- Mad River, Humboldt County, California2 objects
- Madang Province, Momase Region, Papua New Guinea5 objects
- Madera County, California11 objects
- Madhya Pradesh, India4 objects
- Maine1 objects
- Malawi7 objects
- Malay Peninsula, Southeast Asia38 objects
- Malaysia22 objects
- Manaus, Amazonas State, Brazil3 objects
- Mandla, Narmada valley, Madhya Pradesh4 objects
- Mangai, Kenya1 objects
- Manihiki Island, Northern Cook Islands, Cook Islands1 objects
- Maningrida region, Arnhem Land, Northern Territory1 objects
- Manus Province, Bismarck Archipelago, Islands Region1 objects
- Marin County, California287 objects
- Marina Bay, Richmond, Contra Costa County483 objects
- Marquesas, French Polynesia1 objects
- Marsabit, Eastern Province, Kenya6 objects