México (southern Veracruz, Chiapas): Two weeks (26 August–9 September, 2005), largely funded by the Instituto de Ecología, UNAM, with additional support from NSF REVSYS project. REVSYS collaborator, Dr Oscar Francke, accompanied by undergraduate students Milagros Córdova and Abigail Jaimes (undergraduate students from Universidad Autónoma de Morelos) and Alejandro Valdez and Hector Montaño (undergraduate students from the Facultad de Ciencias, UNAM), conducted another trip to survey arachnids at the Lacandona Forest Biosphere Reserve, digressing to visit other localities along the way. Eleven orders of living arachnids were collected during the trip! Buthids are the most abundant scorpions in this part of México, and several species from various groups were collected, including rare (and possibly new) species in the Centruroides thorelli complex. At least one more new diplocentrid was collected at the La Sepultura Biosphere Reserve. The rediscovery of an undescribed species of Vaejovis in the eusthenura group, previously known a single specimen, was also of particular interest.