Cacti identification (4 species)

[GreenBird]

I started a blog to keep track of my new plants and I'm in the process of identifying the species, here some pictures.
Any help is greatly appreciated

1)
[img]https://4.bp.blogspot.com/-A5yY4shHcXk/UIhYZ5BZHeI/AAAAAAAAAXw/1L4baGaiUwY/s1600/unknown_20121024_4.jpg[/img]

2)
[img]https://1.bp.blogspot.com/-a_v6j78v0C0/UIhWZ3INhRI/AAAAAAAAAXo/WIh91aiSAFI/s1600/unknown_20121024_3.jpg[/img]

3)
[img]https://2.bp.blogspot.com/-OfhacS-osfU/UIhVt5vpgyI/AAAAAAAAAXg/nFz1g0PZn78/s1600/unknown_20121024_2.jpg[/img]

4)
[img]https://2.bp.blogspot.com/-TzxJQoMcOQE/UIhUUsPPGeI/AAAAAAAAAXY/I1Qh_StNm7g/s1600/unknown_20121024.jpg[/img]

[Wlady]

Genus Mammillaria. Search here https://www.mammillarias.net/