Genus Bolostromus Ausserer, 1875

Type species. Bolostromus venustus Ausserer, 1875 .

Diagnosis. Bolostromus are distinguished from other American Cyrtaucheniidae (sensus Montes de Oca et al. 2022) as such: eye group rectangular (Figs 2A, 7A) while about three times wider behind in Bolostromoides (see Schiapelli & Gerschmann 1945; pl II); from Acontius by labium subquadrate and presence of serrula (Figs 30D, E), serrula absent and labium longer than wide in the latter (Raven 1985: 126).

Description. Total length: male 2.03–14.01, female 4.57–16.06. CEPHALOTHORAX: Carapace longer than wide, rectangular to hexagonal; margin sinuous; smooth, rugose or reticulate; pars cephalica elevated (Fig. 2C), pars thoracica flat; cephalic groove shallow to deep, without pit (Fig. 2C) or with pit (Fig. 25C, arrow); fovea strongly procurved to straight (Figs 2A, 7A, 51A). Sternum longer than wide (Fig. 2B), in some species considerably elongated (Fig. 38B) smooth or reticulate; sigillae present, posterior one round to oval, anterior and median one often inconspicuous (Fig. 12B). Labium without cuspule, as long as wide (Fig. 10B), or elongated (Fig. 38B). Endites with cuspules; serrula present (Figs 30D, E). Chelicerae with rastellum of 4–23 spines; chelicerae promarin with 6–7 teeth and groove with small denticles (Figs 30B, C); B. stridulator n. sp. with stridulatory organ (Fig. 60D). EYES: Eight eyes in two rows; PME the smallest; in some males eye region on a small mound (Fig. 60C); ocular quadrangle rectangular, sometimes slightly wider posteriorly (Figs 51A, 57A). LEGS: Tarsi I–II and metatarsi I–II with scopulae dense or thin (Figs 2D, 5D); femur IV with pro-apical spines; patella III with spines; males tibiae I with or without megaspine (Figs 45D, 48D arrow); males metatarsi I sometimes with modified setae (Figs 20A, 23D arrow); tarsal claw bipectinate, with 0–23 teeth; third claw present on all legs (Fig. 31C, D); leg formula 4123 or 1423. ABDOMEN: Oval to elongate; uniformly color or with pattern (Figs 4A, 21A).

Natural History. Specimens were collected from 100m in coastal habitat to the Páramo habitat at 3952m. Female were mostly collected within burrows, most male were collected by pitfall traps, malaise traps or hand collected.

Composition. Bolostromus busu n. sp., B. devriesi n. sp., B. epiphyticus n. sp., B. fauna (Simon, 1889), B. fonsecai n. sp., B. gaujoni (Simon, 1889), B. holguinensis Rudloff, 1996, B. hubeni n. sp., B. insularis (Simon, 1892), B. laheredia n. sp., B. italoi n. sp., B. losrios n. sp., B. nischki n. sp., B. panamanus (Petrunkevitch, 1925), B. urku n. sp., B. palenque n. sp. B. primus n. sp., B. pristirana n. sp., B. pulchripes (Simon, 1889), B. riveti Simon, 1903, B. stridulator n. sp., B. valdivia n. sp. (female) and B. venustus Ausserer, 1875 .

Distribution. Cuba, Dominican Republic, St. Vincent, Costa Rica, Panama, Venezuela, Colombia and Ecuador.

Note. Bolostromus suspectus O. Pickard-Cambridge was described from a juvenile specimen from Uganda and is presumed misplaced (WSC 2023).