What do I have here?

I recieved this plant in the divesting of a club member's plants when he could not take care of them. I have several others that are precious and I suspect this one maybe, if only for its size. The spines are pectinate, otherwise the surface is smooth. And what is up with this plant, fatter in the middle, and all dark? Is this dirt or age? Sorry about the sideways image, I can't figure out how to fix it.

Hard to say without the flowers, but I would suggest Mammillaria tlalocii.

I will see what I can do to get them. Thanks much.

Hi, I would agree this is most likely m. crucigera subs. tlalocii. The odd shapes are due to age, the widths of the bands are growth "rings", rather similar to a tree. The plant in time will slowly produce a column, becoming pendulous in shape with age. It usually remains solitary. Flowers should appear as carmine coloured from the plants shoulder rather than the apex.

As an add to, another possibility is that if the flowers turn out not to be red and indeed are white and grow in the usual place from the apex, then it could be m. chionocephala a form of formosa. I see it has a label, anything on there that might give us a clue.

I checked that label which said M. oteroi, I turned it over and found M. tlalocii, so it rests until it blooms. My search was to get it off oteroi, which it surely was not. Here's to a flower!

I would say that confirms it. Its got to be m. tlalocii. Flowers should prove it.