Second part. On the third day, the Author wanted to find Strombocactus corregidorae on its natural habitat and also wanted to visit some Strombocactus disciformis habitats east from Mexico City, close to San Joaquín. Nevertheless, because of the bad condition of the roads and the slow driving, he decided to turn back 6 km away from the S. corregidorae habitat. At 1850 m altitude, he found several S. disciformis specimens dug into slate sediment. North from here, between Pena Blanca and Camargo, at 1670 m altitude he find S. disciformis growing right next to the road on the rocks in a high number. Along the Rio Estorax, he did not find S. disciformis. The vegetation contained there Coryphantha cornifera, Echinocactus platyacanthus, Ferocactus echidne, Cylindropuntia sp., Opuntia microdasys, Astrophytum ornatum and Mammillaria parkinsonii. On the fourth day, he found a miniform of S. disciformis close to Jalpan de Serra. In Santa Rita, he found specimens of the non-accepted Ariocarpus retusus var. scapharostroides taxon living close to the road at 1140 m altitude in a calcareous soil. The deep green plants were retracted into the soil. In San Francisco de Asís he did not managed to find Ariocarpus kotschoubeyanus var. sladkovskyii specimens which were dug out by some animals.