Notes on slender species of the long-jawed spider genus Tetragnatha (Araneae, Tetragnathidae) with description of three new species.

New data about slender orb-weaving species of the cosmopolitan genus Tetragnatha are presented. Tetragnatha chauliodus (Thorell, 1890) and Tetragnatha tenuissima O. Pickard-Cambridge, 1889 are redescribed, including one synonymy for each species and the first record of the first species to the Neotropical region. Also, three new species are herein described, all based on males and females. Tetragnatha megalocera new species is recorded exclusively from Brazil (Espírito Santo, Rio de Janeiro, Rio Grande do Sul and São Paulo states), while Tetragnatha renatoi new species is recorded from Venezuela, Argentina (Misiones) and Brazil (Paraná, Pernambuco, Rio Grande do Sul, Rondônia, Santa Catarina and São Paulo states). Finally, Tetragnatha chiyokoae new species is described from Yunnan province (China) and Okinawa (Japan), with an additional record for Taiwan. Furthermore, Tetragnatha exilima (Mello-Leitão, 1943), Tetragnatha filigastra Mello-Leitão, 1943 and Tetragnatha lactescens (Mello-Leitão, 1947) are nomina dubia.