Ayacachi or Mamariti Group, Cordillera Vilcanota. Steve Webster (USA), John Wilson (New Zealand), Bill Whelen (Australia) and I explored the north side of the Ayacachi group. People on the north call it Mamariti, and I have yet to hear someone refer to it as Ayacachi, although the name is established on early maps. We also found out the Quechua names used by those on the north for the mountains; since they are isolated from the people on the south of the range, many peaks have two or more names. On July 23 we climbed a flattened dome-like peak known both as Huallatani and Qolqepunku on the north side. (There is no local name for it on the south side in Quebradas Kaiko and Kellopampa, but in the Quebrada Kaiko the neighboring peak to the west is called Huallatani; as Qolqepunku is also a common name, on the map to be published, I shall indicate the peak we climbed as Qolqepunku-Huallatani. By altimeter it is c. 5165 meters or 16,945 feet.) We climbed from the valley of Qolqekuchomayo by the northern argillite slopes and the northeast ridge. We traversed toward the Quince Mil-Urcos road on the 24th after an unsuccessful attempt on the northwest ridge of Qohuiñayoq, highest in the Ayacachi group. (This is called Huallpacunca on the south.) We made our way east over the Q’asa (pass) Huallatani into the headwaters of the Kikumayo. On the 25th all but Whelen climbed Sasahuiniy (c. 17,500 feet) up its shattered north-northeast spur. (From the south it would be Qolqepunku IV.) The next day Webster went down to Kiku village and the rest of us crossed Q’asa Sillarura east into the headwaters of the Quebrada Chhektacucho. On the 27th Whelen and I climbed the northwest spur directly above mine workings to a broad glacier platform and took the easy west-northwest ridge to the top of Alayani (c. 17,000 feet). Then we all descended the Quebrada Chhektacucho to Km 133 on the Quince Mil-Urcos road. Note: The Spanish expedition of 1961 proposed many unsuitable names, which are unacceptable to Peruvian map-makers. The local Quechua names are given with the Spanish expedition equivalent in quotation marks: Alayani= “Consuelo” probably; Sasahuiniy (north) or Qolqepunku IV (south)= “Julia”; Qolqepunku I (south) or Kaiko (west)=“Montserrat”; Huillaser- ku=“Barcelona”; Chunticollo=“Guadalupe”; Qoriñacha=“Rosario”. Other corrections appear in A.A.J., 1970.