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Genus Scytodes includes most species of the spider family Scytodidae. Until now, 187 species of the genus have been described. In spite of this great diversity, only three Scytodes species were karyotyped so far. The present paper provides for the first time karyotype analysis of two synanthropic species, Scytodes fusca and Scytodes itapevi. Furthermore, new data on karyotype of Scytodes globula are also provided using conventional and differential cytogenetical procedures. The diploid number in the genus Scytodes varied considerably, namely from 2n = 13 to 2n = 31. The diploid number found in S. globula (2n# = 13) is the lowest in haplogyne spiders with monocentric chromosomes. Except S. globula, this number has been found only in one haplogyne spider with monocentric chromosomes, namely Ochyrocera sp. (Ochyroceratidae). On the contrary, the diploid number of S. fusca (2n# = 31) is one of the highest diploid numbers recorded in haplogyne spiders. The degree of intrageneric variation found in the genus Scytodes is the highest recorded in araneomorph spiders with monocentric chromosomes so far. Some karyotype characteristics (diploid number, chromosome morphology, total chromosome length, and distribution of constitutive heterochromatin) allowed us to postulate a close relationship between S. globula and S. itapevi. According to the karyotype data, S. fusca is not closely related to these two species. This conclusion corroborates a recent taxonomic work that grouped S. globula, S. itapevi, and other four Scytodes species in the Ôglobula groupÕ.

Hersiliidae Thorell is a family of conspicuously long-legged spiders, characterized by extremely elongate posterior lateral spinnerets. To date, it includes 148 species distributed within seven genera, of which Tama Simon is the only one recorded in the Neotropical Region. Of the 23 known Tama species, 18 are exclusively Neotropical. In order to enhance the scientific knowledge on the family and its members this study presents a cladistic analysis and a taxonomic revision of the Neotropical and Nearctic hersilids. The cladistic analysis places the Neotropical and Neartic species in two separate clades, none of which are closely related to the genus Tama. Based on this result, Tama mexicana (O.P.-Cambridge) and T. forcipata (F.O.P.-Cambridge) are transferred to Neotama and three new genera are proposed to include the remaining species: Ypypuera n. gen. to include T. crucifera Vellard and T. vittata (Simon); Iviraiva n. gen. to include T. pachyura Mello-Leitão and T. argentina Mello-Leitão; and Yabisi n. gen to include T. habanensis Franganillo. Based on the taxonomic revision, eight synonymies are proposed: Tama crulsi Mello-Leitão, Tama micrura Mello-Leitão and T. occidentalis Schenkel with Ypypuera crucifera (Vellard); T. brasiliensis Piza and T. karinae Carcavallo with I. pachyura (Mello-Leitão); T. catamarcaensis Carcavallo and T. longipes Carcavallo with I. argentina (Mello-Leitão); and T. guianensis Mello-Leitão with Neotama mexicana (O.P.-Cambridge); three names are placed as nomina dubia: Tama americana (Simon), T. albigastra Mello-Leitão and T. sasaimae Mello-Leitão and four new species are described: Neotama cunhabebe, from São Paulo, Brazil, Neotama obatala, from Bahia, Brazil, Ypypuera esquisita, from Quevedo, Ecuador, and Yabisi guaba, from Pedernales, Dominican Republic. The family Hersiliidae, the genus Neotama and all three new genera, as well as all Neotropical and Nearctic species are redescribed and diagnosed and a identification key is presented.

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 AbstractHuber, B.A., Rheims, C.A., Brescovit, A.D. 2005. Two new species of litterdwelling Metagonia spiders (Araneae, Pholcidae) document both rapid and slow genital evolution. -Acta Zoologica (Stockholm) 86 : 33-40The observation that genitalia, rather than other characters, are useful in distinguishing species has resulted in the statement that genitalia evolve relatively rapidly. In this paper we claim that relatively rapid evolution of genitalia may often be restricted to the shapes, numbers, and sizes of individual structures. In contrast, the more basic pattern, including the presence or absence of structures and their interrelationships (the bauplan), does not seem to evolve more rapidly than other (nongenital) aspects of morphology. We document this idea by contrasting two litter-dwelling pholcid species, Metagonia petropolis sp. n. and M. paranapiacaba sp. n., with their mostly leafdwelling congeners. Significant differences occur with regard to nongenital aspects of morphology as well as shapes of individual genital structures, but the bauplan of their genitalia is basically the same.

In this study we present a redescription of Scytodes championi, S. romitii and S, guttipes. Seven species are newly described: S. panamensis from Panama; S. vaurieorum and S, chiquimula from Guatemala; S. cogu and S. armata from Costa Rica; S. tegucigalpa and S. zamorano from Honduras. Four of these were described as variations of 5'. championi in a recent revision of the species of Central America. New records are presented for S. championi, S. romitii, S. guttipes, S. gertschi and S. cubensis.