Pachistopelma rufonigrum Pocock, 1901, by original designation.

Male and female Pachistopelma differ from most other aviculariines, except Ephebopus, Tapinauchenius and Psalmopoeus by the straight to sligthly procurved first eye row (Fig. 37). Pachistopelma males differ from these genera by having a spinose spur on tibia I and females differ by having a dorso-ventrally flattened abdomen in combination with paired long spermathecae with a slight curvature medially and lacking constrictions or lobes. Additionally, males and females differ from these genera by both the absence of leg spines and the presence of urticating type II hair on the abdomen dorsum (except in mature females, that lack them).

Carapace longer than wide; cephalic region low (mainly in female) (Fig. 34). Cephalic and thoracic striae hardly distinct. Fovea shallow, straight. Chelicerae without rastellum. Eye tubercle low (mainly in female), wider than long (Fig. 36). Clypeus absent (Fig. 37). Anterior eye row straight in female, slightly procurved in male (Fig. 37). Labium wider than long, with 80–150 cuspules concentrated on anterior half. Maxillary lyra absent. Maxilla subrectangular, anterior lobe distinctly produced into conical process, inner angle bearing numerous cuspules (130–200). Sternum longer than wide. Posterior angle not separating coxae IV. Posterior sigilla submarginal, less than one diameter from margin. Leg formula: IV I II III. Clavate trichobothria on distal 2/3 of tarsi I–IV. STC of males and femalewithout teeth. Tarsi I–IV fully scopulated. Scopulae of tarsi and metatarsi I–II extended very laterally giving them a spatulate appearance. Femur IV without retrolateral scopula. Legs lacking spines. Posterior median spinneret with distal article digitiform (Fig. 39). Abdomen dorso-ventrally flattened in female (Figs 34–35). Stridulatory setae absent. Male spur on tibia I, consists of a low elevation with numerous spiniform setae on its tip (Fig. 33). Male palpal bulb globose narrowing abruptly forming long slender embolus, 3 times longer than tegulum length, with a curvature of roughly 45° to retrolateral side, keels absent, tegulum without prolateral depression (Figs 29–31). Two long, uniform, weakly sclerotized spermathecae with slight curvature in their middle (Fig. 32). Cymbium with a short spiniform process (Fig. 49). Type II of urticating hair on abdomen dorsum of immatures and males, absent in mature females.

Pachistopelma rufonigrum Pocock, 1901 (Figs 29–45, 58–61, 67–68, 76–77), Pachistopelma bromelicola sp. n. (Figs 46–57, 62–68, 75, 78–80).

Northeastern Brazil, from the state of Rio Grande do Norte [6°22'S] to state of Bahia [13°25'S], mostly in the coastal region (Fig. 68). Both species of Pachistopelma inhabit tank bromeliads exclusively, e. g. Aechmea aquilega (Dias et al. 2000, Santos et al. 2004); Hohenbergia stellata, Hohenbergia ridley (Dias et al. 2000); Hohenbergia ramageana and Avicularia lingulata (Santos et al. 2004) (Figs 69–80) which can be found in very distinct habitats such as restinga (Figs 72–74), caatinga or even rainforest (Figs 69–71). In the last case, the spiders were in bromeliads that grow mainly on rocky outcrops exposed to direct and intense sunlight.

Pachistopelma juveniles possess a metallic green general pattern, and the dorsum of abdomen having a black longitudinal central stripe and five lateral black stripes that may connect with the central stripe. Adults are brownish to pinkish or blackish, without abdominal pattern (Figs 40–45, 52–57).

Pachistopelma concolor Caporiacco, 1947, lectotype (herein designated), immature male, Guyana, Campo di Marlissa, 31 December (MZUF 507); paralectotype, immature, Guyana, Campo I Demerara (MZUF 505), deposited in Museo Zoologico “La Specola”, Firenze, examined. Specimens have spines on apex of tibiae and metatarsi, lack urticating hair both on abdomen dorsum as well as on prolateral distal femur of palp, first ocular eye row is almost straight, and maxillary lyra is absent. This combination of characters is diagnostic for Tapinauchenius, and, therefore, Pachistopelma concolor Caporiacco, 1947 is transferred to Tapinauchenius concolor (Caporiacco, 1947) comb. n.