On the trapdoor spiders of Mexico: description of the first new species of the spider genus Aptostichus from Mexico and the description of the female of Eucteniza zapatista (Araneae, Mygalomorphae, Euctenizidae)

: A new species of the spider genus Aptostichus Simon, 1891 is described from a cave in Huautla de Jimenez, Oaxaca, Mexico: Aptostichus sabinaesp. n. This species represents the first new species described from Mexico and the southernmost record in North America for the genus so far. Aptostichus sabinaesp. n. represents the forty-first species described for the genus, which has the highest species diversity in the family Euctenizidae. Eucteniza zapatista is redescribed based on five new males and the first known female from the Parque Nacional La Malinche (PNLM), Tlaxcala Mexico. Eucteniza zapatista is the fourth species of the genus where a female is known, and one of fourteen species described for the genus to date.