Declared by Hunt to be probably a later description of M.supertexta, but maintained by Reppenhagen as well as M.supertexta.
Certainly the photograph in Britton and Rose's book, reproduced in Craig "Mammillaria handbook", is clearly the same as Lau collected (LAU1158) and Hunt has made a good case for it representing what was described as M.supertexta.
Referred to M.supertexta
Mammillaria - John Pilbeam pag.330
From "Albert Plapp kakteen"
From "Ento" Ennio Toso collection - Savona