cactuses mammillaria (?)

I recently bought these two small cactuses, which look like mammillaria. Can anyone help me identify them?

http://i194.photobucket.com/albums/z173/allloe/mammillariasp1.jpg

http://i194.photobucket.com/albums/z173/allloe/mammillariasp2.jpg

 

the second one is, the first one notsomuch :)

i wonder what it is, it sure is nice

 

I classified the second tentatively as mammillaria albilanata, but I'm not quite sure...

 

Looks right to me. What's your ID for the first one.

 

For the first one I have no clue...
For the second one, I'm now inclined for mammillaria matudae... what do you think?

Gee, it's so difficult to distinguish them!

 

Well... looking at the pictures I'm still for mammillaria albilanata. It might be a function of age, but yours and the albilanata both have less "fuzz" than the matudae.

 

I've been looking around in the net, and I think now that the first one is a rebutia minuscula.