The majority of the species of the New World litter-inhabiting eyeless weevils belong to groups possessing uncinate tibiae: Molytinae, Cryptorhynchinae, and Cossoninae. The remaining species are Raymondionymini (Erirhininae) and are not included in this work.Eight genera and 40 species with uncinate tibiae are diagnosed and keyed. Caecossonus Gilbert (four species) is revised and the following new species are described: C. continuus (Mexico); C. sylvaticus (Belize). Decuanellus Osella (10 species) is revised and the following new species are described: D. bahamensis (Bahama Islands); D. brevicrus (Virgin Islands); D. iviei (Virgin Islands); D. longirostris (Puerto Rico); D. muchmorei (Virgin Islands). The new genus Kuschelaxius is proposed and the type species K. tomentosus (Puerto Rico) is described from Puerto Rico. The new species K. discifer is described from Hispaniola. No new species are described in the remaining genera: Howdeniola Osella (two species, Colombia); Lymantes Schoenherr (five species, central United States, El Salvador); Neotorneuma Hustache (one species, Chile); Pseudoalaocybites Osella (15 species, Cuba, Jamaica, Colombia, and Venezuela); Pseudocaecocossonus Osella (one species, Cuba). There are many undescribed species in Lymantes and Pseudoalaocybites, and problems precluding much-needed revisions of these genera are detailed.New combinations and a new synonymy are as follows: Bordoniola Osella is transferred to Raymondionymini; Howdeniola is transferred to Cossoninae; Caecossonus negreai Osella is transferred to Pseudoalaocybites (Pseudoalaocybites); Pseudoalaocybites (Pseudoalaocybites) venezuelanus Osella is transferred to P. (Croizatius); Pseudoalaocybites (Croizatius) montanus Osella is a junior synonym of P. (C.) latithorax Osella.Both the geological history of the Caribbean and dispersal by overwater rafting influenced the present distribution patterns of Caecossonus and Decuanellus.

The non-Palaearctic species of the genus Phthitia Enderlein are revised, including descriptions of 30 species, of which 19 are described as new by the first author: P. antillensis, P. bicalyx, P. cercipilus, P. mulroneyi, P. digiseta, P. digistylus, P. lineasterna, P. lobocercus, P. luteocercus, P. luteofrons, P. megocula, P. merida, P. nigrifacies, P. notthomasi, P. obunca, P. occimosa, P. ovicercus, P. quadricercus, and P. spinicalyx. The genera Kimosina Roháček and Aubertinia Richards are newly placed in synonymy with Phthitia, and the following new combinations are given for species previously in Kimosina: Phthitia chilenica (Duda), P. antipoda (Roháček), P. rennelli (Harrison), P. thomasi (Harrison), P. empirica (Hutton), P. levigena (Spuler), P. plumosula (Rondani), P. spinosa (Collin), P. pappi (Roháček), P. glabrescens (Villeneuve), P. ciliata (Duda), P. longisetosa (Dahl), P. sicana (Munari), P. soikai (Munari), and Archicollinella dolichoptera (Richards). Phthitia sanctaehelenae (Richards) is given as a new combination for Aubertinia sanctaehelenae Richards. Limosina phycophila Richards is a new junior synonym of Archicollinella caerulea (Duda). A key, illustrations, descriptions of adults, distribution maps, and a phylogeny are provided for all New World and Pacific species. The puparium of P. empirica is described. A lectotype is designated for P. chilenica.

From the endemic New World halyine genus Brochymena, two genera are recognized. New morphological characters at the generic level are described. Parabrochymena, new genus, with Pentatoma arborea Say as type species, is erected to contain 10 taxa formerly included in Brochymena. New combinations are Parabrochymena aculeata (Distant), P. apiculata (Van Duzee), P. arborea (Say), P. barberi barberi (Ruckes), P. barberi diluta (Blatchley), P. cuspidata (Distant), P. enigmatica (Ruckes), P. florida (Ruckes), P. haedula (Stål), and P. poeyi (Guérin-Méneville). Brochymena is redefined with 20 taxa: B. affinis Van Duzee, B. cariosa Stål, B. carolinensis (Westwood), B. chelonoides Ruckes, B. dilata Ruckes, B. exardentia Ruckes, B. hoppingi Van Duzee, B. humeralis Ruckes, B. laevigata Ruckes, B. lineata Ruckes, B. marginella Stål, B. myops Stål, B. parva Ruckes, B. punctata punctata Van Duzee, B. punctata pallida Blatchley, B. pilatei Van Duzee, B. quadripustulata (Fabricius), B. splendida Ruckes, B. sulcata Van Duzee, and B. tenebrosa Walker. Four synonymies are established: B. marginella Stål = B. carolinensis (Westwood); B. pilatei Van Duzee = B. sulcata Van Duzee; B. laevigata Ruckes = B. myops Stål; B. exardentia Ruckes = B. lineata Ruckes. Lectotypes are designated for B. affinis Van Duzee, B. cariosa Stål, B. myops Stål, B. punctata pallida Blatchley, and B. p. punctata Van Duzee. Species groups of Brochymena are characterized, and a key to all taxa is presented for the first time. As appropriate, for each species of Brochymena, the following are provided: citation of original description, synonymies, type material, diagnosis, description, geographical distribution, taxonomic comments, natural history, and illustrations of important structural characters. Chorological affinities are presented and systematic relationships are hypothesized.

The Nearctic Region genera of Phoridae are revised, and it is shown that the current classification into three subfamilies is inadequate. The hypothesis that the most closely related taxa to the Phoridae are the Sciadoceridae and Ironomyiidae is supported. Use of these outgroups to polarize character states in the Phoridae allows the reorganization of this family into five subfamilies: Hypocerinae, Phorinae, Aenigmatiinae, Conicerinae, and Metopininae. The newly re-defined Phorinae is the adelphotaxon (sister-group) of the Aenigmatiinae + Conicerinae + Metopininae, among which the relationships are unresolved. The hypocerines are the adelphotaxon of all other extant Phoridae. Within the Hypocerinae the relationships of the 15 included world genera are hypothesized, and three new genera are proposed. The relationships of the eight world phorine genera are only partly resolved. The Aenigmatiinae is organized into two tribes: Aenigmatiini and Diplonevrini. The relationships of the seven world genera of Diplonevrini are hypothesized, whereas those of the Aenigmatiini are not discussed. The six world conicerine genera are revised and their relationships hypothesized. In the Metopininae, two major groups are recognized, the Metopina-group and the Megaselia-group. Beckerina Malloch is the adelphotaxon of these two groups, whereas Rhopica Schmitz and Triphleba Rondani are successive outgroups of all metopinines. The Metopina-group is mostly tropical in distribution and is not discussed further. The Megaselia-group is partially organized into the Gymnophora-subgroup and the Apocephalus-subgroup. Species-level revisions of genera are needed before further progress can be made in this family, because the distribution of character states is insufficiently known. Genera in great need of revision include Peromitra Enderlein, Chaetopleurophora Schmitz, Megaselia Rondani, and Apocephalus Coquillett.