We describe a new species of Pseudoeurycea from the northernmost high peak of the Sierra de Juárez, Oaxaca, México. This species belongs to the P. juarezi group, a monophyletic assemblage restricted to northern Oaxaca and comprising three species: P. juarezi,…

A new species of Spauligodon collected from Cnemidophorus mexicanus and C. deppii is described in this study. The species is placed in Spauligodon because the caudal alae start at the level of the precloacal papillae and embed the adcloacal papillae.…

Rhabdochona ahuehuellensis n. sp. is described from the Balsas goodeid, Ilyodon whitei. The distinctive characters are cuticular elevations in the middle of the prostom, tricuspid ending of the distal part of the left spicule combined with a scoop shape, and…

Two new species of freshwater crabs of the genus Tehuana from the states of Tabasco and Oaxaca, Mexico, are described, and a new diagnosis for the genus is presented. Tehuana chontalpaensis, new species, was collected in a mountain river in…

A new species of parasitic nematode, Cystoopsis atractostei (Trichinelloidea: Cystoopsidae), is described based on female specimens recovered from the subcutaneous tissue of the tropical gar, Atractosteus tropicus Gill (Lepisosteiformes: Lepisosteidae), from 2 localities (Canal Nueva Esperanza and Canal Tabasquillo) of…

A new species, Vaejovis atenango, belonging to the V. punctipalpi group is described from southern Mexico; this group was previously only known from the North American deserts in the USA and northern Mexico. This geographically discontinuous distribution is similar to…

Field exploration and floristic research have revealed another plant species endemic to the peninsula of Baja California, Mexico. A new shrubby species (Amyris certerae)from the Sierra Guadalupe and Sierra de la Giganta, Baja California Sur, is described here. Distribution, associated…

A new species, Gochnatia hiriartiana Medrano, Villaseñor & Medina (Asteraceae, tribe Mutisieae), of the desert scrubland of the state of Hidalgo, Mexico, is described. Its distinctive morphological traits are discussed and compared with the other Mexican species of the genus…

The new species Pachychernes tamaulipensis is described from all freeliving stages collected in nests of the packrat, Neotoma micropus, in Tamaulipas, Mexico. This species is related to P. shelfordi, P. zehorum, P. attenuatus and P. baileyi; all of them form…

Sciurodendrium bravohollisa e n,sp.(Heligrnone llidae) is described as an intestinal parasite of 2 squirrels. Sciurus aureogaster Cuvier,1829, collected from Los Robles, Municipio de Tlalnepantla, Morelos State, Mexico. The new species differs from all other congeners in possessing a very well…