Stenoterommata iguazu is a species of mygalomorph spiders of Argentina, named after its type locality: Iguazú, Misiones. Females are distinguished from other species in the genus, except S. platense, by the 2 + 2 spermathecae; from S. platense, they are distinguished by the outer spermathecal lobe having a single receptaculum. Males are distinguished from other species, except S. platense, by having a thin, well-sclerotized embolus and the bulbal duct with an even curvature; from S. platense, by the sudden tapering apical portion of the bulbal duct and the slightly smaller size.
Stenoterommata uruguai is a mygalomorph spider of Argentina, named after its type locality: Salto del Uruguaí. This species is distinguished from other Stenoterommata by its spermathecae consisting of a single dome bearing numerous receptacula. Its spermathecae are similar to those of S. quena, but in S. uruguai the basal dome is more rounded.
Stenoterommata quena is a species of mygalomorph spiders of Argentina, named after its type locality: La Quena, Salta Province. Females are recognized by the numerous spines on prolateral patella III. The rastellum is stronger, and the maxillae are shorter, than in other species of its genus. The presence of preening combs in metatarsi I is also unusual.
Stenoterommata palmar is a mygalomorph spider of Argentina, named after its type locality: Parque Nacional El Palmar, Entre Rios. Females differ from other three-clawed Stenoterommata in the spermathecae having one triangular dome with a single receptaculum arising from its base; males are most similar to those of S. tenuistyla, but lack short ventral spines on the metatarsus I, and have a long, curved spine on the apical third of their ventral tibia I. Its burrowing behaviour is similar to that of S. tenuistyla.
Stenoterommata crassistyla is a species of mygalomorph spiders of Argentina, named after its wide embolus (stylus) in males, distinguishing this species from the sympatric S. tenuistyla. Its behaviour is similar to the latter species as well. Females are distinguished from other Stenoterommata having multireceptaculate spermathecae by the presence of inferior tarsal claws on the anterior legs. Males have the palpal tibia with a basal notch at either side of the base, and swollen. The species is distinguished from S. tenuistyla by lacking the short spines on the male metatarsus I, characteristic of said species.
Acanthogonatus confusus is a mygalomorph spider of Argentina and Chile, its name referring to the confusion between this species and A. subcalpeianus. Males are recognized by their long palpi, together with the absence of a tibial apophysis; females are recognized by the spermathecae.
Acanthogonatus huaquen is a mygalomorph spider of Chile, its name referring to its type locality: Huaquén, Chile. Males are recognized from other two-clawed Acanthogonatus by the bulb with a lateral keel delimiting a concave area; females by the spermathecae with an almost conical basal mound and its duct arising from its tip.
Acanthogonatus quilocura is a mygalomorph spider of Chile, its name referring to the seemingly unending number of species within this genus. Males are similar to those of A. tacuariensis, from which are distinguished by a curved metatarsus I; female spermathecae are characteristic in having a strongly bent duct arising from the base of a blunt basal dome.
Acanthogonatus centralis is a mygalomorph spider of Argentina, its name referring to its distribution, being one of the most common mygalomorphs in central Argentina. Females are most similar to those of A. parana, are distinguished by the widened fundus of the spermathecae. Males, on the other hand, are recognized by the smooth, keelless bulb, in combination with a well-developed tibial apophysis.
Acanthogonatus parana is a mygalomorph spider of Argentina, its name referring to its type locality: Paraná, Entre Ríos. Females are most similar to those of A. centralis, but are distinguished by the narrow fundus of the spermathecae.
Acanthogonatus nahuelbuta is a mygalomorph spider of Chile, named after its type locality: Piedra del Águila, Parque Nacional Nahuel-Buta, Malleco. Males differ from A. patagallina by having the basal portion of the bulb less rounded and the basal loop of the bulbal duct less sinuous; and from those of A. hualpen by the differently shaped embolus and the palpal tibia with the apical two-thirds tapering gradually and having thickened setae.
Acanthogonatus hualpen is a mygalomorph spider of Chile, named after its type locality: Hualpén, Concepción, Bío Bío Region. Males can be distinguished from those of A. nahuelbuta and A. patagallina by the shaped of the bulb's apex, and by the palpal tibia being wide in the basal two-thirds with thickened setae along the apical one-third of the retrolateral face.
Acanthogonatus vilches is a mygalomorph spider of Chile, named after its type locality: Gil de Vilches, Talca, Region VII. Females differ from other species in the nahuelbuta group by their less modified spermathecae.
Chilelopsis minima is a species of mygalomorph spiders found in Chile. It formerly belonged in the genus Flamencopsis. The specific name was given because it is the smallest member of the tribe Diplothelopsini.
Lycinus caldera is a mygalomorph spider of Chile, named after its type locality: Caldera, Copiapó, Region III. Males are distinguished from L. gajardoi by the larger cymbium, the thinner and more numerous modified cymbial setae and the shorter embolus, and from those of all other species in the tribe by having cymbial setae directed backwards. Females are distinguished from other Chilean species of Lycinus by the spermathecae with two or three receptacula on each side.
Chilelopsis serena is a species of mygalomorph spiders of Chile, named after its type locality: La Serena, Elqui, Region IV. Males differ from those both C. calderoni and C. puertoviejo in the absence of a patch of setae on the apical tibia I, and also in the palpal tibia having dorsal spines and the bulbal duct being abruptly narrowed at the apex. Females differ from the two other species by their divided spermathecae.
Chilelopsis puertoviejo is a species of mygalomorph spiders of Chile, named after its type locality: Puerto Viejo, Copiapó, Region III. The species is most similar to C. calderoni, but differs in having the distal portion of the male bulbal duct less sinuous and the female spermathecae of uniform width, with no differentiated fundus. It differs from C. serena in the undivided female spermathecae and the male tibia I having a dense apical patch of setae.
Chilelopsis calderoni is a species of mygalomorph spiders of Chile, named after Dr Raúl Calderón. Males differ from C. puertoviejo in the more sinuous distal portion of the bulbal duct; females differ in the spermathecae with a distinct fundus and a narrowed duct. Males differ from C. serena by the presence of a dense patch of setae on the anterior tibiae, females in the undivided spermathecae.
Lycinus tofo is a mygalomorph spider of Chile, named after its type locality: El Tofo, Coquimbo Region. Males are distinguished by the palpal bulb, more abruptly tapered than in other species of the genus; females by the long, slender, spiraled spermathecal receptacula.
Chaco tucumana is a species of mygalomorph spiders of Argentina, named after its type locality: Tucumán. This species differs from C. obscura in the shorter male embolus and the shorter female spermathecal ducts. From other species of the genus it differs in its dark uniform color, the flexible anterior female tarsi, the denser scopulae on the posterior tarsi, and the female spermathecae without a basal protuberance. As in C. obscura, smaller specimens are much lighter in color, and it has darker spots that are evident on the sides of its cephalic region, the apex of femora, base of the patellae and lateral tibiae and dorsal abdomen. Larger specimens are much darker, almost black, with no visible pattern.
