Mammillaria viescensis
Hunt refers this taxon to M.stella-de-tacubaja, together with M.gasseriana, but the Fitz Maurices in collaboration with Charles Glass make a sound case for retaining M.gasseriana, referring M.viescensis to synonymy with it.
Mammillaria - John Pilbeam pag.339
Mammillaria viescensis WTH 323
WTH 323 - South side of the hills at La Cuchilla - Coahuila - Mexicó
From "Ento" Ennio Toso collection - Savona